From bb1ac6bde906fe51cd9e2d28b2293fc1008fde19 Mon Sep 17 00:00:00 2001
From: Arnav Sacheti <36746504+arnavsacheti@users.noreply.github.com>
Date: Sun, 19 Oct 2025 00:06:45 -0700
Subject: [PATCH] decoder compiles

---
 src/peakrdl_busdecoder/__peakrdl__.py         |   4 +-
 src/peakrdl_busdecoder/body/__init__.py       |  13 +-
 src/peakrdl_busdecoder/body/body.py           |   3 +
 .../body/combinational_body.py                |   6 +-
 src/peakrdl_busdecoder/body/for_loop_body.py  |   5 +-
 src/peakrdl_busdecoder/body/if_body.py        |  16 +-
 src/peakrdl_busdecoder/body/struct_body.py    |  15 ++
 .../body/while_loop_body.py                   |  13 --
 .../cpuif/apb3/apb3_cpuif.py                  |  35 +---
 .../cpuif/apb3/apb3_tmpl.sv                   |  20 +--
 .../cpuif/apb4/apb4_cpuif.py                  |  34 +---
 .../cpuif/apb4/apb4_cpuif_flat.py             |   1 +
 .../cpuif/apb4/apb4_tmpl.sv                   |  99 +++++++-----
 src/peakrdl_busdecoder/cpuif/base_cpuif.py    |  37 ++---
 src/peakrdl_busdecoder/decoder.py             | 153 ++++++++++--------
 .../{scan_design.py => design_scanner.py}     |  12 +-
 src/peakrdl_busdecoder/design_state.py        |  72 +++++++++
 src/peakrdl_busdecoder/exporter.py            | 102 ++++--------
 src/peakrdl_busdecoder/module_tmpl.sv         |  35 +---
 src/peakrdl_busdecoder/utils.py               |  59 +------
 src/peakrdl_busdecoder/validate_design.py     |  17 +-
 21 files changed, 335 insertions(+), 416 deletions(-)
 create mode 100644 src/peakrdl_busdecoder/body/struct_body.py
 delete mode 100644 src/peakrdl_busdecoder/body/while_loop_body.py
 rename src/peakrdl_busdecoder/{scan_design.py => design_scanner.py} (79%)
 create mode 100644 src/peakrdl_busdecoder/design_state.py

diff --git a/src/peakrdl_busdecoder/__peakrdl__.py b/src/peakrdl_busdecoder/__peakrdl__.py
index c2b4718..23493aa 100644
--- a/src/peakrdl_busdecoder/__peakrdl__.py
+++ b/src/peakrdl_busdecoder/__peakrdl__.py
@@ -65,13 +65,13 @@ class Exporter(ExporterSubcommandPlugin):
 
         return cpuifs
 
-    def add_exporter_arguments(self, arg_group: "argparse._ActionsContainer") -> None:
+    def add_exporter_arguments(self, arg_group: "argparse.ArgumentParser") -> None: # type: ignore
         cpuifs = self.get_cpuifs()
 
         arg_group.add_argument(
             "--cpuif",
             choices=cpuifs.keys(),
-            default="apb3",
+            default="apb4",
             help="Select the CPU interface protocol to use [apb3]",
         )
 
diff --git a/src/peakrdl_busdecoder/body/__init__.py b/src/peakrdl_busdecoder/body/__init__.py
index 1584657..d8c7574 100644
--- a/src/peakrdl_busdecoder/body/__init__.py
+++ b/src/peakrdl_busdecoder/body/__init__.py
@@ -1,15 +1,12 @@
 from .body import Body, SupportsStr
-from .for_loop_body import ForLoopBody
-from .while_loop_body import WhileLoopBody
-from .if_body import IfBody
 from .combinational_body import CombinationalBody
-
+from .for_loop_body import ForLoopBody
+from .if_body import IfBody
 
 __all__ = [
     "Body",
-    "SupportsStr",
-    "ForLoopBody",
-    "WhileLoopBody",
-    "IfBody",
     "CombinationalBody",
+    "ForLoopBody",
+    "IfBody",
+    "SupportsStr",
 ]
diff --git a/src/peakrdl_busdecoder/body/body.py b/src/peakrdl_busdecoder/body/body.py
index d37f337..203f325 100644
--- a/src/peakrdl_busdecoder/body/body.py
+++ b/src/peakrdl_busdecoder/body/body.py
@@ -15,3 +15,6 @@ class Body:
     def __add__(self, other: SupportsStr) -> Self:
         self.lines.append(other)
         return self
+
+    def __bool__(self) -> bool:
+        return bool(self.lines)
diff --git a/src/peakrdl_busdecoder/body/combinational_body.py b/src/peakrdl_busdecoder/body/combinational_body.py
index 8c090a4..75fa6ad 100644
--- a/src/peakrdl_busdecoder/body/combinational_body.py
+++ b/src/peakrdl_busdecoder/body/combinational_body.py
@@ -1,8 +1,10 @@
 from textwrap import indent
+
 from .body import Body
 
+
 class CombinationalBody(Body):
     def __str__(self) -> str:
         return f"""always_comb begin
-            {indent(super().__str__(), "\t")}
-        end"""
\ No newline at end of file
+            {indent(super().__str__(), "    ")}
+        end"""
diff --git a/src/peakrdl_busdecoder/body/for_loop_body.py b/src/peakrdl_busdecoder/body/for_loop_body.py
index fdf28e1..560aad0 100644
--- a/src/peakrdl_busdecoder/body/for_loop_body.py
+++ b/src/peakrdl_busdecoder/body/for_loop_body.py
@@ -1,9 +1,10 @@
 from textwrap import indent
+
 from .body import Body
 
 
 class ForLoopBody(Body):
-    def __init__(self, type: str, iterator: str, dim: int):
+    def __init__(self, type: str, iterator: str, dim: int) -> None:
         super().__init__()
         self._type = type
         self._iterator = iterator
@@ -11,5 +12,5 @@ class ForLoopBody(Body):
 
     def __str__(self) -> str:
         return f"""for ({self._type} {self._iterator} = 0; {self._iterator} < {self._dim}; {self._iterator}++) begin
-{indent(super().__str__(), "\t")}
+{indent(super().__str__(), "    ")}
 end"""
diff --git a/src/peakrdl_busdecoder/body/if_body.py b/src/peakrdl_busdecoder/body/if_body.py
index 7fb89d5..13d0f06 100644
--- a/src/peakrdl_busdecoder/body/if_body.py
+++ b/src/peakrdl_busdecoder/body/if_body.py
@@ -1,16 +1,18 @@
 from __future__ import annotations
+
+from textwrap import indent
 from types import EllipsisType
 from typing import Self
+
 from .body import Body, SupportsStr
 
 
 class IfBody(Body):
-    def __init__(self, *, indent: int = 4) -> None:
+    def __init__(self) -> None:
         super().__init__()
         # (None means 'else')
         self._branches: list[tuple[SupportsStr | None, Body]] = []
         self._has_else = False
-        self._indent = " " * indent
 
     # --- Item access: if/else-if via condition; else via Ellipsis/None ---
     def __getitem__(self, condition: SupportsStr | EllipsisType | None) -> Body:
@@ -63,7 +65,7 @@ class IfBody(Body):
         ) -> bool:
             return False
 
-    def cm(self, condition: SupportsStr | None) -> "IfBody._BranchCtx":
+    def cm(self, condition: SupportsStr | None) -> IfBody._BranchCtx:
         """Use with: with ifb.cm('cond') as b: ...  ; use None for else."""
         return IfBody._BranchCtx(self, condition)
 
@@ -79,6 +81,12 @@ class IfBody(Body):
                 out.append("else begin")
             body_str = str(body)
             if body_str:
-                out.extend(self._indent + ln for ln in body_str.splitlines())
+                out.extend(indent(ln, "    ") for ln in body_str.splitlines())
             out.append("end")
         return "\n".join(out)
+
+    def __len__(self) -> int:
+        return len(self._branches)
+
+    def __bool__(self) -> bool:
+        return bool(self._branches)
diff --git a/src/peakrdl_busdecoder/body/struct_body.py b/src/peakrdl_busdecoder/body/struct_body.py
new file mode 100644
index 0000000..215d955
--- /dev/null
+++ b/src/peakrdl_busdecoder/body/struct_body.py
@@ -0,0 +1,15 @@
+from textwrap import indent
+
+from .body import Body
+
+
+class StructBody(Body):
+    def __init__(self, name: str, packed: bool = True) -> None:
+        super().__init__()
+        self._name = name
+        self._packed = packed
+
+    def __str__(self) -> str:
+        return f"""typedef struct {"packed " if self._packed else ""} {{
+{indent(super().__str__(), "    ")}
+}} {self._name};"""
diff --git a/src/peakrdl_busdecoder/body/while_loop_body.py b/src/peakrdl_busdecoder/body/while_loop_body.py
deleted file mode 100644
index 980c2bd..0000000
--- a/src/peakrdl_busdecoder/body/while_loop_body.py
+++ /dev/null
@@ -1,13 +0,0 @@
-from textwrap import indent
-from .body import Body
-
-
-class WhileLoopBody(Body):
-    def __init__(self, condition: str):
-        super().__init__()
-        self._condition = condition
-
-    def __str__(self) -> str:
-        return f"""while ({self._condition}) begin
-            {indent(super().__str__(), "\t")}
-        end"""
diff --git a/src/peakrdl_busdecoder/cpuif/apb3/apb3_cpuif.py b/src/peakrdl_busdecoder/cpuif/apb3/apb3_cpuif.py
index 524a490..9e68009 100644
--- a/src/peakrdl_busdecoder/cpuif/apb3/apb3_cpuif.py
+++ b/src/peakrdl_busdecoder/cpuif/apb3/apb3_cpuif.py
@@ -42,37 +42,4 @@ class APB3Cpuif(BaseCpuif):
         if idx is not None:
             return f"{base}[{idx}].{signal}"
 
-        raise ValueError("Must provide an index for arrayed interface signals")
-
-    def get_address_predicate(self, node: AddressableNode) -> str:
-        """
-        Returns a SystemVerilog expression that evaluates to true when the
-        address on the bus matches the address range of the given node.
-        """
-
-        addr_mask = (1 << self.addr_width) - 1
-        addr = node.absolute_address & addr_mask
-        size = node.size
-        if size == 0:
-            raise ValueError("Node size must be greater than 0")
-        if (addr % size) != 0:
-            raise ValueError("Node address must be aligned to its size")
-
-        # Calculate the address range of the node
-        addr_start = addr
-        addr_end = addr + size - 1
-        if addr_end > addr_mask:
-            raise ValueError("Node address range exceeds address width")
-
-        if addr_start == addr_end:
-            return f"({self.signal('PADDR')} == 'h{addr_start:X})"
-
-        return f"({self.signal('PADDR')} >= 'h{addr_start:X} && {self.signal('PADDR')} <= 'h{addr_end:X})"
-
-    def get_address_decode_condition(self, node: AddressableNode) -> str:
-        """
-        Returns a SystemVerilog expression that evaluates to true when the
-        address on the bus matches the address range of the given node.
-        """
-        addr_pred = self.get_address_predicate(node)
-        return addr_pred
\ No newline at end of file
+        raise ValueError("Must provide an index for arrayed interface signals")
\ No newline at end of file
diff --git a/src/peakrdl_busdecoder/cpuif/apb3/apb3_tmpl.sv b/src/peakrdl_busdecoder/cpuif/apb3/apb3_tmpl.sv
index 4067454..7495ff3 100644
--- a/src/peakrdl_busdecoder/cpuif/apb3/apb3_tmpl.sv
+++ b/src/peakrdl_busdecoder/cpuif/apb3/apb3_tmpl.sv
@@ -16,14 +16,14 @@ assign cpuif_rd_en = !{{cpuif.signal("PWRITE")}};
 
 {%- for child in cpuif.addressable_children -%}
 {%- if child is array -%}
-for (genvar g_idx = 0; g_idx < N_{{child.inst_name|upper}}S; g_idx++) begin : g_passthrough_{{child.inst_name|lower}}
-    assign {{cpuif.signal("PCLK", child, "g_idx")}}    = {{cpuif.signal("PCLK")}};
-    assign {{cpuif.signal("PRESETn", child, "g_idx")}} = {{cpuif.signal("PRESETn")}};
-    assign {{cpuif.signal("PSELx", child, "g_idx")}}    = (cpuif_wr_req[{{loop.index}}] || cpuif_rd_req[{{loop.index}}]) ? 1'b1 : 1'b0;
-    assign {{cpuif.signal("PENABLE", child, "g_idx")}} = {{cpuif.signal("PENABLE")}};
-    assign {{cpuif.signal("PWRITE", child, "g_idx")}}  = (cpuif_wr_req[{{loop.index}}]) ? 1'b1 : 1'b0;
-    assign {{cpuif.signal("PADDR", child, "g_idx")}}   = cpuif_wr_addr{{child|address_slice}};
-    assign {{cpuif.signal("PWDATA", child, "g_idx")}}  = cpuif_wr_data;
+for (genvar gi = 0; gi < N_{{child.inst_name|upper}}S; gi++) begin : g_passthrough_{{child.inst_name|lower}}
+    assign {{cpuif.signal("PCLK", child, "gi")}}    = {{cpuif.signal("PCLK")}};
+    assign {{cpuif.signal("PRESETn", child, "gi")}} = {{cpuif.signal("PRESETn")}};
+    assign {{cpuif.signal("PSELx", child, "gi")}}   = (cpuif_wr_req[{{loop.index}}] || cpuif_rd_req[{{loop.index}}]) ? 1'b1 : 1'b0;
+    assign {{cpuif.signal("PENABLE", child, "gi")}} = {{cpuif.signal("PENABLE")}};
+    assign {{cpuif.signal("PWRITE", child, "gi")}}  = (cpuif_wr_req[{{loop.index}}]) ? 1'b1 : 1'b0;
+    assign {{cpuif.signal("PADDR", child, "gi")}}   = {{child|address_slice(cpuif_addr="cpuif_wr_addr")}};
+    assign {{cpuif.signal("PWDATA", child, "gi")}}  = cpuif_wr_data;
     assign cpuif_rd_ack[loop.index] = {{cpuif.signal("PREADY", child)}};
     assign cpuif_rd_data[loop.index] = {{cpuif.signal("PRDATA", child)}};
     assign cpuif_rd_err[loop.index] = {{cpuif.signal("PSLVERR", child)}};
@@ -31,10 +31,10 @@ end
 {%- else -%}
 assign {{cpuif.signal("PCLK", child)}}    = {{cpuif.signal("PCLK")}};
 assign {{cpuif.signal("PRESETn", child)}} = {{cpuif.signal("PRESETn")}};
-assign {{cpuif.signal("PSELx", child)}}    = (cpuif_wr_sel[{{loop.index0}}] || cpuif_rd_sel[{{loop.index0}}]) ? 1'b1 : 1'b0;
+assign {{cpuif.signal("PSELx", child)}}   = (cpuif_wr_sel[{{loop.index0}}] || cpuif_rd_sel[{{loop.index0}}]) ? 1'b1 : 1'b0;
 assign {{cpuif.signal("PENABLE", child)}} = {{cpuif.signal("PENABLE")}};
 assign {{cpuif.signal("PWRITE", child)}}  = (cpuif_wr_req[{{loop.index}}]) ? 1'b1 : 1'b0;
-assign {{cpuif.signal("PADDR", child)}}   = cpuif_wr_addr{{child|address_slice}};
+assign {{cpuif.signal("PADDR", child)}}   = {{child|address_slice(cpuif_addr="cpuif_wr_addr")}};
 assign {{cpuif.signal("PWDATA", child)}}  = cpuif_wr_data;
 assign cpuif_rd_ack[loop.index] = {{cpuif.signal("PREADY", child)}};
 assign cpuif_rd_data[loop.index] = {{cpuif.signal("PRDATA", child)}};
diff --git a/src/peakrdl_busdecoder/cpuif/apb4/apb4_cpuif.py b/src/peakrdl_busdecoder/cpuif/apb4/apb4_cpuif.py
index da46846..7705c0b 100644
--- a/src/peakrdl_busdecoder/cpuif/apb4/apb4_cpuif.py
+++ b/src/peakrdl_busdecoder/cpuif/apb4/apb4_cpuif.py
@@ -1,4 +1,5 @@
 from systemrdl.node import AddressableNode
+
 from ..base_cpuif import BaseCpuif
 
 
@@ -44,36 +45,3 @@ class APB4Cpuif(BaseCpuif):
             return f"{base}[{idx}].{signal}"
 
         raise ValueError("Must provide an index for arrayed interface signals")
-
-    def get_address_predicate(self, node: AddressableNode) -> str:
-        """
-        Returns a SystemVerilog expression that evaluates to true when the
-        address on the bus matches the address range of the given node.
-        """
-
-        addr_mask = (1 << self.addr_width) - 1
-        addr = node.absolute_address & addr_mask
-        size = node.size
-        if size == 0:
-            raise ValueError("Node size must be greater than 0")
-        if (addr % size) != 0:
-            raise ValueError("Node address must be aligned to its size")
-
-        # Calculate the address range of the node
-        addr_start = addr
-        addr_end = addr + size - 1
-        if addr_end > addr_mask:
-            raise ValueError("Node address range exceeds address width")
-
-        if addr_start == addr_end:
-            return f"({self.signal('PADDR')} == 'h{addr_start:X})"
-
-        return f"({self.signal('PADDR')} >= 'h{addr_start:X} && {self.signal('PADDR')} <= 'h{addr_end:X})"
-
-    def get_address_decode_condition(self, node: AddressableNode) -> str:
-        """
-        Returns a SystemVerilog expression that evaluates to true when the
-        address on the bus matches the address range of the given node.
-        """
-        addr_pred = self.get_address_predicate(node)
-        return addr_pred
diff --git a/src/peakrdl_busdecoder/cpuif/apb4/apb4_cpuif_flat.py b/src/peakrdl_busdecoder/cpuif/apb4/apb4_cpuif_flat.py
index 7f28645..c97b202 100644
--- a/src/peakrdl_busdecoder/cpuif/apb4/apb4_cpuif_flat.py
+++ b/src/peakrdl_busdecoder/cpuif/apb4/apb4_cpuif_flat.py
@@ -1,4 +1,5 @@
 from systemrdl.node import AddressableNode
+
 from ..base_cpuif import BaseCpuif
 
 
diff --git a/src/peakrdl_busdecoder/cpuif/apb4/apb4_tmpl.sv b/src/peakrdl_busdecoder/cpuif/apb4/apb4_tmpl.sv
index d0a8c88..670ae7c 100644
--- a/src/peakrdl_busdecoder/cpuif/apb4/apb4_tmpl.sv
+++ b/src/peakrdl_busdecoder/cpuif/apb4/apb4_tmpl.sv
@@ -1,4 +1,4 @@
-{%- if cpuif.is_interface -%}
+{%- if cpuif.is_interface %}
 `ifndef SYNTHESIS
     initial begin
         assert_bad_addr_width: assert($bits({{cpuif.signal("PADDR")}}) >= {{ds.package_name}}::{{ds.module_name|upper}}_MIN_ADDR_WIDTH)
@@ -7,55 +7,76 @@
             else $error("Interface data width of %0d is incorrect. Shall be %0d bits", $bits({{cpuif.signal("PWDATA")}}), {{ds.package_name}}::{{ds.module_name|upper}}_DATA_WIDTH);
     end
 `endif
-{% endif -%}
+{%- endif %}
 
 assign cpuif_req   = {{cpuif.signal("PSELx")}};
 assign cpuif_wr_en = {{cpuif.signal("PWRITE")}};
 assign cpuif_wr_data = {{cpuif.signal("PWDATA")}};
 assign cpuif_rd_en = !{{cpuif.signal("PWRITE")}};
 
-{%- for child in cpuif.addressable_children -%}
-{%- if child is array -%}
-for (genvar g_{{child.inst_name|lower}}_idx = 0; g_{{child.inst_name|lower}}_idx < N_{{child.inst_name|upper}}S; g_{{child.inst_name|lower}}_idx++) begin : g_passthrough_{{child.inst_name|lower}}
-    assign {{self.signal("PCLK", child, f"g_{child.inst_name.lower()}_idx")}}    = {{self.signal("PCLK")}};
-    assign {{self.signal("PRESETn", child, f"g_{child.inst_name.lower()}_idx")}} = {{self.signal("PRESETn")}};
-    assign {{self.signal("PSELx", child, f"g_{child.inst_name.lower()}_idx")}}    = (cpuif_wr_sel[{{loop.index}}] || cpuif_rd_sel[{{loop.index}}]) ? 1'b1 : 1'b0;
-    assign {{self.signal("PENABLE", child, f"g_{child.inst_name.lower()}_idx")}} = {{self.signal("PENABLE")}};
-    assign {{self.signal("PWRITE", child, f"g_{child.inst_name.lower()}_idx")}}  = (cpuif_wr_sel[{{loop.index}}]) ? 1'b1 : 1'b0;
-    assign {{self.signal("PADDR", child, f"g_{child.inst_name.lower()}_idx")}}   = {{cpuif.get_address_slice(cpuif_wr_addr, child)}};
-    assign {{self.signal("PPROT", child, f"g_{child.inst_name.lower()}_idx")}}   = {{self.signal("PPROT")}};
-    assign {{self.signal("PWDATA", child, f"g_{child.inst_name.lower()}_idx")}}  = cpuif_wr_data;
-    assign {{self.signal("PSTRB", child, f"g_{child.inst_name.lower()}_idx")}}   = {{self.signal("PSTRB")}};
-    assign cpuif_rd_ack[loop.index] = {{cpuif.signal("PREADY", child)}};
-    assign cpuif_rd_data[loop.index] = {{cpuif.signal("PRDATA", child)}};
-    assign cpuif_rd_err[loop.index] = {{cpuif.signal("PSLVERR", child)}};
-end
-{%- else -%}
-assign {{self.signal("PCLK", child)}}    = {{self.signal("PCLK")}};
-assign {{self.signal("PRESETn", child)}} = {{self.signal("PRESETn")}};
-assign {{self.signal("PSELx", child)}}    = (cpuif_wr_sel[{{loop.index0}}] || cpuif_rd_sel[{{loop.index0}}]) ? 1'b1 : 1'b0;
-assign {{self.signal("PENABLE", child)}} = {{self.signal("PENABLE")}};
-assign {{self.signal("PWRITE", child)}}  = cpuif_wr_sel[{{loop.index}}] ? 1'b1 : 1'b0;
-assign {{self.signal("PADDR", child)}}   = {{cpuif.get_address_slice(cpuif_wr_addr, child)}};
-assign {{self.signal("PPROT", child)}}   = {{self.signal("PPROT")}};
-assign {{self.signal("PWDATA", child)}}  = cpuif_wr_data;
-assign {{self.signal("PSTRB", child)}}   = {{self.signal("PSTRB")}};
-assign cpuif_rd_ack[loop.index] = {{cpuif.signal("PREADY", child)}};
-assign cpuif_rd_data[loop.index] = {{cpuif.signal("PRDATA", child)}};
-assign cpuif_rd_err[loop.index] = {{cpuif.signal("PSLVERR", child)}};
-{%- endif -%}
-{%- endfor -%}
+//--------------------------------------------------------------------------
+// Fanout CPU Bus interface signals
+//--------------------------------------------------------------------------
 
+// {%- for child in cpuif.addressable_children -%}
+// {%- if child is array %}
+// for (genvar gi = 0; gi < N_{{child.inst_name|upper}}S; gi++) begin : g_passthrough_{{child.inst_name|lower}}
+//     assign {{cpuif.signal("PCLK", child, "gi")}}    = {{cpuif.signal("PCLK")}};
+//     assign {{cpuif.signal("PRESETn", child, "gi")}} = {{cpuif.signal("PRESETn")}};
+//     assign {{cpuif.signal("PSELx", child, "gi")}}   = (cpuif_wr_sel[{{loop.index}}] || cpuif_rd_sel[{{loop.index}}]) ? 1'b1 : 1'b0;
+//     assign {{cpuif.signal("PENABLE", child, "gi")}} = {{cpuif.signal("PENABLE")}};
+//     assign {{cpuif.signal("PWRITE", child, "gi")}}  = (cpuif_wr_sel[{{loop.index}}]) ? 1'b1 : 1'b0;
+//     assign {{cpuif.signal("PADDR", child, "gi")}}   = {{child|address_slice(cpuif_addr="cpuif_wr_addr")}};
+//     assign {{cpuif.signal("PPROT", child, "gi")}}   = {{cpuif.signal("PPROT")}};
+//     assign {{cpuif.signal("PWDATA", child, "gi")}}  = cpuif_wr_data;
+//     assign {{cpuif.signal("PSTRB", child, "gi")}}   = {{cpuif.signal("PSTRB")}};
+//     assign cpuif_rd_ack[{{loop.index}}] = {{cpuif.signal("PREADY", child, "gi")}};
+//     assign cpuif_rd_data[{{loop.index}}] = {{cpuif.signal("PRDATA", child, "gi")}};
+//     assign cpuif_rd_err[{{loop.index}}] = {{cpuif.signal("PSLVERR", child, "gi")}};
+// end
+// {%- else %}
+// assign {{cpuif.signal("PCLK", child)}}    = {{cpuif.signal("PCLK")}};
+// assign {{cpuif.signal("PRESETn", child)}} = {{cpuif.signal("PRESETn")}};
+// assign {{cpuif.signal("PSELx", child)}}   = (cpuif_wr_sel[{{loop.index}}] || cpuif_rd_sel[{{loop.index}}]) ? 1'b1 : 1'b0;
+// assign {{cpuif.signal("PENABLE", child)}} = {{cpuif.signal("PENABLE")}};
+// assign {{cpuif.signal("PWRITE", child)}}  = cpuif_wr_sel[{{loop.index}}] ? 1'b1 : 1'b0;
+// assign {{cpuif.signal("PADDR", child)}}   = {{child|address_slice(cpuif_addr="cpuif_wr_addr")}};
+// assign {{cpuif.signal("PPROT", child)}}   = {{cpuif.signal("PPROT")}};
+// assign {{cpuif.signal("PWDATA", child)}}  = cpuif_wr_data;
+// assign {{cpuif.signal("PSTRB", child)}}   = {{cpuif.signal("PSTRB")}};
+// assign cpuif_rd_ack[{{loop.index}}] = {{cpuif.signal("PREADY", child)}};
+// assign cpuif_rd_data[{{loop.index}}] = {{cpuif.signal("PRDATA", child)}};
+// assign cpuif_rd_err[{{loop.index}}] = {{cpuif.signal("PSLVERR", child)}};
+// {%- endif -%}
+// {%- endfor %}
+
+
+//--------------------------------------------------------------------------
+// Fanin CPU Bus interface signals
+//--------------------------------------------------------------------------
 always_comb begin
     {{cpuif.signal("PREADY")}} = 1'b0;
     {{cpuif.signal("PRDATA")}} = '0;
     {{cpuif.signal("PSLVERR")}} = 1'b0;
 
-    for(int i = 0; i < {{cpuif.addressable_children | length}}; i++) begin
-        if (cpuif_rd_sel[i]) begin
-            {{cpuif.signal("PREADY")}} = cpuif_rd_ack[i];
-            {{cpuif.signal("PRDATA")}} = cpuif_rd_data[i];
-            {{cpuif.signal("PSLVERR")}} = cpuif_rd_err[i];
-        end
+
+{%- for child in cpuif.addressable_children -%}
+{%- if loop.first %}
+    if (cpuif_rd_sel.{{child|get_path}}) begin
+{%- else %}
+    end else if (cpuif_rd_sel.{{child|get_path}}) begin
+{%- endif %}
+        {{cpuif.signal("PREADY")}} = cpuif_rd_ack[{{loop.index}}];
+        {{cpuif.signal("PRDATA")}} = cpuif_rd_data[{{loop.index}}];
+        {{cpuif.signal("PSLVERR")}} = cpuif_rd_err[{{loop.index}}];
+{%- endfor %}
     end
+
+    // for(int i = 0; i < {{cpuif.addressable_children | length}}; i++) begin
+    //     if (cpuif_rd_sel[i]) begin
+    //         {{cpuif.signal("PREADY")}} = cpuif_rd_ack[i];
+    //         {{cpuif.signal("PRDATA")}} = cpuif_rd_data[i];
+    //         {{cpuif.signal("PSLVERR")}} = cpuif_rd_err[i];
+    //     end
+    // end
 end
\ No newline at end of file
diff --git a/src/peakrdl_busdecoder/cpuif/base_cpuif.py b/src/peakrdl_busdecoder/cpuif/base_cpuif.py
index 72e9028..13bf734 100644
--- a/src/peakrdl_busdecoder/cpuif/base_cpuif.py
+++ b/src/peakrdl_busdecoder/cpuif/base_cpuif.py
@@ -5,7 +5,7 @@ from typing import TYPE_CHECKING
 import jinja2 as jj
 from systemrdl.node import AddressableNode
 
-from ..utils import clog2, is_pow2, roundup_pow2
+from ..utils import clog2, get_indexed_path, is_pow2, roundup_pow2
 
 if TYPE_CHECKING:
     from ..exporter import BusDecoderExporter
@@ -83,6 +83,7 @@ class BaseCpuif:
         jj_env.filters["is_pow2"] = is_pow2  # type: ignore
         jj_env.filters["roundup_pow2"] = roundup_pow2  # type: ignore
         jj_env.filters["address_slice"] = self.get_address_slice  # type: ignore
+        jj_env.filters["get_path"] = lambda x: get_indexed_path(self.exp.ds.top_node, x, "i") # type: ignore
 
         context = {
             "cpuif": self,
@@ -92,33 +93,13 @@ class BaseCpuif:
         template = jj_env.get_template(self.template_path)
         return template.render(context)
 
-    def get_address_slice(self, node: AddressableNode) -> str:
-        """
-        Returns a SystemVerilog expression that extracts the address bits
-        relevant to the given node.
-        """
-        addr_mask = (1 << self.addr_width) - 1
-        addr = node.absolute_address & addr_mask
+    def get_address_slice(self, node: AddressableNode, cpuif_addr: str = "cpuif_addr") -> str:
+        addr = node.raw_absolute_address - self.exp.ds.top_node.raw_absolute_address
         size = node.size
-        if size == 0:
-            raise ValueError(f"Node size '{size:#X}' must be greater than 0")
-        if (addr % size) != 0:
-            raise ValueError(f"Node address '{addr:#X}' must be aligned to its size '{size:#X}'")
 
-        # Calculate the address range of the node
-        addr_start = addr
-        addr_end = addr + size - 1
-        if addr_end > addr_mask:
-            raise ValueError("Node address range exceeds address width")
+        addr_msb = clog2(addr + size) - 1
+        addr_lsb = clog2(addr)
 
-        # Calculate the number of bits needed to represent the size
-        size_bits = size.bit_length() - 1
-        if size_bits < 0:
-            size_bits = 0
-
-        if size_bits >= self.addr_width:
-            # Node covers entire address space, so return full address
-            return ""
-
-        # Extract the relevant bits from PADDR
-        return f"[{self.addr_width - 1}:{size_bits}]"
+        if addr_msb == addr_lsb:
+            return f"{cpuif_addr}[{addr_lsb}]"
+        return f"{cpuif_addr}[{addr_msb}:{addr_lsb}]"
diff --git a/src/peakrdl_busdecoder/decoder.py b/src/peakrdl_busdecoder/decoder.py
index 4b49232..38330b9 100644
--- a/src/peakrdl_busdecoder/decoder.py
+++ b/src/peakrdl_busdecoder/decoder.py
@@ -1,72 +1,92 @@
 from collections import deque
+from enum import Enum
 
 from systemrdl.node import AddressableNode
 from systemrdl.walker import RDLListener, RDLSimpleWalker, WalkerAction
 
 from .body import Body, ForLoopBody, IfBody
+from .design_state import DesignState
 from .sv_int import SVInt
+from .utils import get_indexed_path
+
+
+class DecodeLogicFlavor(Enum):
+    READ = "rd"
+    WRITE = "wr"
+
+    @property
+    def cpuif_address(self) -> str:
+        return f"cpuif_{self.value}_addr"
+
+    @property
+    def cpuif_select(self) -> str:
+        return f"cpuif_{self.value}_sel"
 
 
 class AddressDecode:
-    def __init__(self, node: AddressableNode, addr_width: int) -> None:
-        self._node = node
-        self._addr_width = addr_width
+    def __init__(self, flavor: DecodeLogicFlavor, ds: DesignState) -> None:
+        self._flavor = flavor
+        self._ds = ds
 
     def walk(self) -> str:
         walker = RDLSimpleWalker()
-        dlg = DecodeLogicGenerator(self)
-        walker.walk(self._node, dlg, skip_top=True)
+        dlg = DecodeLogicGenerator(self._flavor, self._ds)
+        walker.walk(self._ds.top_node, dlg, skip_top=True)
         return str(dlg)
 
-    @property
-    def node(self) -> AddressableNode:
-        return self._node
-
-    @property
-    def addr_width(self) -> int:
-        return self._addr_width
-
 
 class DecodeLogicGenerator(RDLListener):
-    cpuif_addr_signal = "addr"
-    cpuif_sel_prefix = "cpuif_"
-
     def __init__(
         self,
-        address_decoder: AddressDecode,
-        max_depth: int = 1,
+        flavor: DecodeLogicFlavor,
+        ds: DesignState,
     ) -> None:
-        self._address_decoder = address_decoder
-        self._depth = 0
-        self._max_depth = max_depth
+        self._ds = ds
+        self._flavor = flavor
 
-        self._stack: list[Body] = [IfBody()]
-        self._conditions: deque[str] = deque()
-        self._select_signal = [f"{self.cpuif_sel_prefix}{address_decoder.node.inst_name}"]
+        self._decode_stack: deque[Body] = deque()  # Tracks decoder body
+        self._cond_stack: deque[str] = deque()  # Tracks conditions nested for loops
+        self._array_stride_stack: deque[int] = deque()  # Tracks nested array strids
 
-        # Stack to keep track of array strides for nested arrayed components
-        self._array_stride_stack: list[int] = []
+        # Initial Stack Conditions
+        self._decode_stack.append(IfBody())
 
-    def enter_AddressableComponent(self, node: AddressableNode) -> WalkerAction | None:
+    def cpuif_addr_predicate(self, node: AddressableNode) -> list[str]:
         # Generate address bounds
-        addr_width = self._address_decoder.addr_width
+        addr_width = self._ds.addr_width
         l_bound = SVInt(
-            node.raw_absolute_address - self._address_decoder.node.raw_absolute_address,
+            node.raw_address_offset,
             addr_width,
         )
         u_bound = l_bound + SVInt(node.total_size, addr_width)
 
         # Handle arrayed components
-        l_bound_str = str(l_bound)
-        u_bound_str = str(u_bound)
+        l_bound_comp = [str(l_bound)]
+        u_bound_comp = [str(u_bound)]
         for i, stride in enumerate(self._array_stride_stack):
-            l_bound_str += f" + (({addr_width})'(i{i}) * {SVInt(stride, addr_width)})"
-            u_bound_str += f" + (({addr_width})'(i{i}) * {SVInt(stride, addr_width)})"
+            l_bound_comp.append(f"({addr_width}'(i{i})*{SVInt(stride, addr_width)})")
+            u_bound_comp.append(f"({addr_width}'(i{i})*{SVInt(stride, addr_width)})")
 
-        # Generate condition string
-        condition = (
-            f"({self.cpuif_addr_signal} >= ({l_bound_str})) && ({self.cpuif_addr_signal} < ({u_bound_str}))"
-        )
+        # Generate Conditions
+        return [
+            f"{self._flavor.cpuif_address} >= ({'+'.join(l_bound_comp)})",
+            f"{self._flavor.cpuif_address} < ({'+'.join(u_bound_comp)})",
+        ]
+
+    def cpuif_prot_predicate(self, node: AddressableNode) -> list[str]:
+        if self._flavor == DecodeLogicFlavor.READ:
+            # Can we have PROT on read? (axi full?)
+            return []
+
+        # TODO: Implement
+        return []
+
+    def enter_AddressableComponent(self, node: AddressableNode) -> WalkerAction | None:
+        conditions: list[str] = []
+        conditions.extend(self.cpuif_addr_predicate(node))
+        conditions.extend(self.cpuif_prot_predicate(node))
+
+        condition = " && ".join(f"({c})" for c in conditions)
 
         if node.array_dimensions:
             assert node.array_stride is not None, "Array stride should be defined for arrayed components"
@@ -80,26 +100,25 @@ class DecodeLogicGenerator(RDLListener):
             self._array_stride_stack.extend(strides)
 
         # Generate condition string and manage stack
-        signal = node.inst_name
-        if isinstance(self._stack[-1], IfBody) and node.array_dimensions:
+        if isinstance(self._decode_stack[-1], IfBody) and node.array_dimensions:
             # arrayed component with new if-body
-            self._conditions.append(condition)
-            for dim in node.array_dimensions:
+            self._cond_stack.append(condition)
+            for i, dim in enumerate(
+                node.array_dimensions,
+                start=len(self._array_stride_stack) - len(node.array_dimensions),
+            ):
                 fb = ForLoopBody(
                     "int",
-                    f"i{self._depth}",
+                    f"i{i}",
                     dim,
                 )
-                self._stack.append(fb)
-                signal += f"[i{self._depth}]"
-                self._depth += 1
+                self._decode_stack.append(fb)
 
-            self._stack.append(IfBody())
-        elif isinstance(self._stack[-1], IfBody):
+            self._decode_stack.append(IfBody())
+        elif isinstance(self._decode_stack[-1], IfBody):
             # non-arrayed component with if-body
-            with self._stack[-1].cm(condition) as b:
-                b += f"{'.'.join([*self._select_signal, signal])} = 1'b1;"
-        self._select_signal.append(signal)
+            with self._decode_stack[-1].cm(condition) as b:
+                b += f"{self._flavor.cpuif_select}.{get_indexed_path(self._ds.top_node, node)} = 1'b1;"
 
         # if node.external:
         #     return WalkerAction.SkipDescendants
@@ -107,26 +126,34 @@ class DecodeLogicGenerator(RDLListener):
         return WalkerAction.Continue
 
     def exit_AddressableComponent(self, node: AddressableNode) -> None:
-        self._select_signal.pop()
-
         if not node.array_dimensions:
             return
 
-        ifb = self._stack.pop()
-        self._stack[-1] += ifb
+        ifb = self._decode_stack.pop()
+        if ifb:
+            self._decode_stack[-1] += ifb
+        else:
+            self._decode_stack[-1] += (
+                f"{self._flavor.cpuif_select}.{get_indexed_path(self._ds.top_node, node)} = 1'b1;"
+            )
 
         for _ in node.array_dimensions:
-            self._depth -= 1
+            b = self._decode_stack.pop()
+            if not b:
+                continue
 
-            b = self._stack.pop()
-            if b.lines:
-                if isinstance(self._stack[-1], IfBody):
-                    with self._stack[-1].cm(self._conditions.pop()) as parent_b:
-                        parent_b += b
-                else:
-                    self._stack[-1] += b
+            if isinstance(self._decode_stack[-1], IfBody):
+                with self._decode_stack[-1].cm(self._cond_stack.pop()) as parent_b:
+                    parent_b += b
+            else:
+                self._decode_stack[-1] += b
 
             self._array_stride_stack.pop()
 
     def __str__(self) -> str:
-        return str(self._stack[-1])
+        body = self._decode_stack[-1]
+        if isinstance(body, IfBody):
+            with body.cm(...) as b:
+                b += f"{self._flavor.cpuif_select}.bad_addr = 1'b1;"
+
+        return str(body)
diff --git a/src/peakrdl_busdecoder/scan_design.py b/src/peakrdl_busdecoder/design_scanner.py
similarity index 79%
rename from src/peakrdl_busdecoder/scan_design.py
rename to src/peakrdl_busdecoder/design_scanner.py
index 0ba2bfd..871b4b7 100644
--- a/src/peakrdl_busdecoder/scan_design.py
+++ b/src/peakrdl_busdecoder/design_scanner.py
@@ -1,12 +1,10 @@
 from typing import TYPE_CHECKING
 
-from systemrdl.node import RegNode
+from systemrdl.node import AddressableNode, AddrmapNode, Node, RegNode
 from systemrdl.walker import RDLListener, RDLWalker, WalkerAction
 
 if TYPE_CHECKING:
-    from systemrdl.node import AddressableNode, AddrmapNode, Node
-
-    from .exporter import DesignState
+    from .design_state import DesignState
 
 
 class DesignScanner(RDLListener):
@@ -22,7 +20,7 @@ class DesignScanner(RDLListener):
         self.msg = self.top_node.env.msg
 
     @property
-    def top_node(self) -> "AddrmapNode":
+    def top_node(self) -> AddrmapNode:
         return self.ds.top_node
 
     def do_scan(self) -> None:
@@ -30,7 +28,7 @@ class DesignScanner(RDLListener):
         if self.msg.had_error:
             self.msg.fatal("Unable to export due to previous errors")
 
-    def enter_Component(self, node: "Node") -> WalkerAction | None:
+    def enter_Component(self, node: Node) -> WalkerAction:
         if node.external and (node != self.top_node):
             # Do not inspect external components. None of my business
             return WalkerAction.SkipDescendants
@@ -41,7 +39,7 @@ class DesignScanner(RDLListener):
 
         return WalkerAction.Continue
 
-    def enter_AddressableComponent(self, node: "AddressableNode") -> None:
+    def enter_AddressableComponent(self, node: AddressableNode) -> None:
         if node.external and node != self.top_node:
             self.ds.has_external_addressable = True
             if not isinstance(node, RegNode):
diff --git a/src/peakrdl_busdecoder/design_state.py b/src/peakrdl_busdecoder/design_state.py
new file mode 100644
index 0000000..05263cb
--- /dev/null
+++ b/src/peakrdl_busdecoder/design_state.py
@@ -0,0 +1,72 @@
+from typing import TypedDict
+
+from systemrdl.node import AddrmapNode
+from systemrdl.rdltypes.user_enum import UserEnum
+
+from .design_scanner import DesignScanner
+from .identifier_filter import kw_filter as kwf
+from .utils import clog2
+
+
+class DesignStateKwargs(TypedDict, total=False):
+    reuse_hwif_typedefs: bool
+    module_name: str
+    package_name: str
+    address_width: int
+    cpuif_unroll: bool
+
+
+class DesignState:
+    """
+    Dumping ground for all sorts of variables that are relevant to a particular
+    design.
+    """
+
+    def __init__(self, top_node: AddrmapNode, kwargs: DesignStateKwargs) -> None:
+        self.top_node = top_node
+        msg = top_node.env.msg
+
+        # ------------------------
+        # Extract compiler args
+        # ------------------------
+        self.reuse_hwif_typedefs: bool = kwargs.pop("reuse_hwif_typedefs", True)
+        self.module_name: str = kwargs.pop("module_name", None) or kwf(self.top_node.inst_name)
+        self.package_name: str = kwargs.pop("package_name", None) or f"{self.module_name}_pkg"
+        user_addr_width: int | None = kwargs.pop("address_width", None)
+
+        self.cpuif_unroll: bool = kwargs.pop("cpuif_unroll", False)
+
+        # ------------------------
+        # Info about the design
+        # ------------------------
+        self.cpuif_data_width = 0
+
+        # Track any referenced enums
+        self.user_enums: list[type[UserEnum]] = []
+
+        self.has_external_addressable = False
+        self.has_external_block = False
+
+        # Scan the design to fill in above variables
+        DesignScanner(self).do_scan()
+
+        if self.cpuif_data_width == 0:
+            # Scanner did not find any registers in the design being exported,
+            # so the width is not known.
+            # Assume 32-bits
+            msg.warning(
+                "Addrmap being exported only contains external components. Unable to infer the CPUIF bus width. Assuming 32-bits.",
+                self.top_node.inst.def_src_ref,
+            )
+            self.cpuif_data_width = 32
+
+        # ------------------------
+        # Min address width encloses the total size AND at least 1 useful address bit
+        self.addr_width = max(clog2(self.top_node.size), clog2(self.cpuif_data_width // 8) + 1)
+
+        if user_addr_width is None:
+            return
+
+        if user_addr_width < self.addr_width:
+            msg.fatal(f"User-specified address width shall be greater than or equal to {self.addr_width}.")
+        self.addr_width = user_addr_width
diff --git a/src/peakrdl_busdecoder/exporter.py b/src/peakrdl_busdecoder/exporter.py
index 82dcae0..fbeeb14 100644
--- a/src/peakrdl_busdecoder/exporter.py
+++ b/src/peakrdl_busdecoder/exporter.py
@@ -1,53 +1,63 @@
 import os
 from datetime import datetime
 from importlib.metadata import version
-from typing import TYPE_CHECKING, Any
+from pathlib import Path
+from typing import TYPE_CHECKING, TypedDict
 
 import jinja2 as jj
 from systemrdl.node import AddrmapNode, RootNode
-from systemrdl.rdltypes.user_enum import UserEnum
+from typing_extensions import Unpack
 
 from .cpuif import BaseCpuif
 from .cpuif.apb4 import APB4Cpuif
-from .decoder import AddressDecode
+from .decoder import AddressDecode, DecodeLogicFlavor
+from .design_state import DesignState
 from .identifier_filter import kw_filter as kwf
-from .scan_design import DesignScanner
 from .sv_int import SVInt
-from .utils import clog2
 from .validate_design import DesignValidator
 
+
+class ExporterKwargs(TypedDict, total=False):
+    cpuif_cls: type[BaseCpuif]
+    module_name: str
+    package_name: str
+    address_width: int
+    cpuif_unroll: bool
+    reuse_hwif_typedefs: bool
+
+
 if TYPE_CHECKING:
     pass
 
 
 class BusDecoderExporter:
     cpuif: BaseCpuif
-    address_decode: AddressDecode
-    ds: "DesignState"
+    address_decode: type[AddressDecode]
+    ds: DesignState
 
-    def __init__(self, **kwargs: Any) -> None:
+    def __init__(self, **kwargs: Unpack[ExporterKwargs]) -> None:
         # Check for stray kwargs
         if kwargs:
             raise TypeError(f"got an unexpected keyword argument '{next(iter(kwargs.keys()))}'")
 
-        loader = jj.ChoiceLoader(
+        fs_loader = jj.FileSystemLoader(Path(__file__).parent)
+        c_loader = jj.ChoiceLoader(
             [
-                jj.FileSystemLoader(os.path.dirname(__file__)),
+                fs_loader,
                 jj.PrefixLoader(
-                    {
-                        "base": jj.FileSystemLoader(os.path.dirname(__file__)),
-                    },
+                    {"base": fs_loader},
                     delimiter=":",
                 ),
             ]
         )
 
         self.jj_env = jj.Environment(
-            loader=loader,
+            loader=c_loader,
             undefined=jj.StrictUndefined,
         )
+        self.jj_env.filters["kwf"] = kwf
 
-    def export(self, node: RootNode | AddrmapNode, output_dir: str, **kwargs: Any) -> None:
+    def export(self, node: RootNode | AddrmapNode, output_dir: str, **kwargs: Unpack[ExporterKwargs]) -> None:
         """
         Parameters
         ----------
@@ -68,7 +78,7 @@ class BusDecoderExporter:
         address_width: int
             Override the CPU interface's address width. By default, address width
             is sized to the contents of the busdecoder.
-        unroll: bool
+        cpuif_unroll: bool
             Unroll arrayed addressable nodes into separate instances in the CPU
             interface. By default, arrayed nodes are kept as arrays.
         """
@@ -88,7 +98,7 @@ class BusDecoderExporter:
 
         # Construct exporter components
         self.cpuif = cpuif_cls(self)
-        self.address_decode = AddressDecode(top_node, self.ds.addr_width)
+        self.address_decode = AddressDecode
 
         # Validate that there are no unsupported constructs
         DesignValidator(self).do_validate()
@@ -99,8 +109,8 @@ class BusDecoderExporter:
             "version": version("peakrdl-busdecoder"),
             "cpuif": self.cpuif,
             "address_decode": self.address_decode,
+            "DecodeLogicFlavor": DecodeLogicFlavor,
             "ds": self.ds,
-            "kwf": kwf,
             "SVInt": SVInt,
         }
 
@@ -115,59 +125,3 @@ class BusDecoderExporter:
         template = self.jj_env.get_template("module_tmpl.sv")
         stream = template.stream(context)
         stream.dump(module_file_path)
-
-
-class DesignState:
-    """
-    Dumping ground for all sorts of variables that are relevant to a particular
-    design.
-    """
-
-    def __init__(self, top_node: AddrmapNode, kwargs: Any) -> None:
-        self.top_node = top_node
-        msg = top_node.env.msg
-
-        # ------------------------
-        # Extract compiler args
-        # ------------------------
-        self.reuse_hwif_typedefs: bool = kwargs.pop("reuse_hwif_typedefs", True)
-        self.module_name: str = kwargs.pop("module_name", None) or kwf(self.top_node.inst_name)
-        self.package_name: str = kwargs.pop("package_name", None) or (self.module_name + "_pkg")
-        user_addr_width: int | None = kwargs.pop("address_width", None)
-
-        self.cpuif_unroll: bool = kwargs.pop("cpuif_unroll", False)
-
-        # ------------------------
-        # Info about the design
-        # ------------------------
-        self.cpuif_data_width = 0
-
-        # Track any referenced enums
-        self.user_enums: list[type[UserEnum]] = []
-
-        self.has_external_addressable = False
-        self.has_external_block = False
-
-        # Scan the design to fill in above variables
-        DesignScanner(self).do_scan()
-
-        if self.cpuif_data_width == 0:
-            # Scanner did not find any registers in the design being exported,
-            # so the width is not known.
-            # Assume 32-bits
-            msg.warning(
-                "Addrmap being exported only contains external components. Unable to infer the CPUIF bus width. Assuming 32-bits.",
-                self.top_node.inst.def_src_ref,
-            )
-            self.cpuif_data_width = 32
-
-        # ------------------------
-        # Min address width encloses the total size AND at least 1 useful address bit
-        self.addr_width = max(clog2(self.top_node.size), clog2(self.cpuif_data_width // 8) + 1)
-
-        if user_addr_width is not None:
-            if user_addr_width < self.addr_width:
-                msg.fatal(
-                    f"User-specified address width shall be greater than or equal to {self.addr_width}."
-                )
-            self.addr_width = user_addr_width
diff --git a/src/peakrdl_busdecoder/module_tmpl.sv b/src/peakrdl_busdecoder/module_tmpl.sv
index 402051a..9f6cb7b 100644
--- a/src/peakrdl_busdecoder/module_tmpl.sv
+++ b/src/peakrdl_busdecoder/module_tmpl.sv
@@ -39,8 +39,11 @@ module {{ds.module_name}}
     //--------------------------------------------------------------------------
     // Child instance signals
     //--------------------------------------------------------------------------
-    logic [{{cpuif.addressable_children | length}}-1:0] cpuif_wr_sel;
-    logic [{{cpuif.addressable_children | length}}-1:0] cpuif_rd_sel;
+    typedef struct packed {
+        
+    } cpuif_sel_t;
+    cpuif_sel_t cpuif_wr_sel;
+    cpuif_sel_t cpuif_rd_sel;
 
     //--------------------------------------------------------------------------
     // Slave <-> Internal CPUIF <-> Master
@@ -56,19 +59,7 @@ module {{ds.module_name}}
 
         if (cpuif_req && cpuif_wr_en) begin
             // A write request is pending
-            {%- for child in cpuif.addressable_children -%}
-            {%- if loop.first -%}
-            if {{child|address_decode}} begin
-            {%- else -%}
-            end else if {{child|address_decode}} begin
-            {%- endif -%}
-                // Address matched for {{child.inst_name}} 
-                cpuif_wr_sel[{{loop.index}}] = 1'b1;
-            {%- endfor -%}
-            end else begin
-                // No address match, all select signals remain 0
-                cpuif_wr_err = 1'b1; // Indicate error on no match
-            end
+            {{address_decode(DecodeLogicFlavor.WRITE, ds).walk()|indent(12)}}
         end else begin
             // No write request, all select signals remain 0
         end
@@ -83,19 +74,7 @@ module {{ds.module_name}}
 
         if (cpuif_req && cpuif_rd_en) begin
             // A read request is pending
-            {%- for child in cpuif.addressable_children -%}
-            {%- if loop.first -%}
-            if {{child|address_decode}} begin
-            {%- else -%}
-            end else if {{child|address_decode}} begin
-            {%- endif -%}
-                // Address matched for {{child.inst_name}} 
-                cpuif_rd_sel[{{loop.index}}] = 1'b1;
-            {%- endfor -%}
-            end else begin
-                // No address match, all select signals remain 0
-                cpuif_rd_err = 1'b1; // Indicate error on no match
-            end
+            {{address_decode(DecodeLogicFlavor.READ, ds).walk()|indent(12)}}
         end else begin
             // No read request, all select signals remain 0
         end
diff --git a/src/peakrdl_busdecoder/utils.py b/src/peakrdl_busdecoder/utils.py
index c42c991..0f838c5 100644
--- a/src/peakrdl_busdecoder/utils.py
+++ b/src/peakrdl_busdecoder/utils.py
@@ -1,17 +1,16 @@
 import re
 from re import Match
-from typing import overload
 
 from systemrdl.node import AddrmapNode, Node
 from systemrdl.rdltypes.references import PropertyReference
 
 from .identifier_filter import kw_filter as kwf
-from .sv_int import SVInt
 
 
-def get_indexed_path(top_node: Node, target_node: Node) -> str:
+def get_indexed_path(top_node: Node, target_node: Node, indexer: str = "i") -> str:
     """
-    TODO: Add words about indexing and why i'm doing this. Copy from logbook
+    Get the relative path from top_node to target_node, replacing any unknown
+    array indexes with incrementing iterators (i0, i1, ...).
     """
     path = target_node.get_rel_path(top_node, empty_array_suffix="[!]")
 
@@ -21,7 +20,7 @@ def get_indexed_path(top_node: Node, target_node: Node) -> str:
             self.i = 0
 
         def __call__(self, match: Match[str]) -> str:
-            s = f"i{self.i}"
+            s = f"{indexer}{self.i}"
             self.i += 1
             return s
 
@@ -54,13 +53,10 @@ def ref_is_internal(top_node: AddrmapNode, ref: Node | PropertyReference) -> boo
 
     For the sake of this exporter, root signals are treated as internal.
     """
-    # current_node: Optional[Node]
-    if isinstance(ref, Node):
-        current_node = ref
-    elif isinstance(ref, PropertyReference):
+    if isinstance(ref, PropertyReference):
         current_node = ref.node
     else:
-        raise RuntimeError
+        current_node = ref
 
     while current_node is not None:
         if current_node == top_node:
@@ -77,46 +73,3 @@ def ref_is_internal(top_node: AddrmapNode, ref: Node | PropertyReference) -> boo
     # A root signal was referenced, which dodged the top addrmap
     # This is considered internal for this exporter
     return True
-
-
-@overload
-def do_slice(value: SVInt, high: int, low: int) -> SVInt: ...
-@overload
-def do_slice(value: str, high: int, low: int) -> str: ...
-def do_slice(value: SVInt | str, high: int, low: int) -> SVInt | str:
-    if isinstance(value, str):
-        # If string, assume this is an identifier. Append bit-slice
-        if high == low:
-            return f"{value}[{low}]"
-        else:
-            return f"{value}[{high}:{low}]"
-    else:
-        # it is an SVInt literal. Slice it down
-        mask = (1 << (high + 1)) - 1
-        v = (value.value & mask) >> low
-
-        if value.width is not None:
-            w = high - low + 1
-        else:
-            w = None
-
-        return SVInt(v, w)
-
-
-@overload
-def do_bitswap(value: SVInt) -> SVInt: ...
-@overload
-def do_bitswap(value: str) -> str: ...
-def do_bitswap(value: SVInt | str) -> SVInt | str:
-    if isinstance(value, str):
-        # If string, assume this is an identifier. Wrap in a streaming operator
-        return "{<<{" + value + "}}"
-    else:
-        # it is an SVInt literal. bitswap it
-        assert value.width is not None  # width must be known!
-        v = value.value
-        vswap = 0
-        for _ in range(value.width):
-            vswap = (vswap << 1) + (v & 1)
-            v >>= 1
-        return SVInt(vswap, value.width)
diff --git a/src/peakrdl_busdecoder/validate_design.py b/src/peakrdl_busdecoder/validate_design.py
index c0b9b77..4528b15 100644
--- a/src/peakrdl_busdecoder/validate_design.py
+++ b/src/peakrdl_busdecoder/validate_design.py
@@ -1,7 +1,7 @@
 from typing import TYPE_CHECKING
 
 from systemrdl.node import AddressableNode, AddrmapNode, FieldNode, Node, RegfileNode, RegNode, SignalNode
-from systemrdl.rdltypes import PropertyReference
+from systemrdl.rdltypes.references import PropertyReference
 from systemrdl.walker import RDLListener, RDLWalker, WalkerAction
 
 from .utils import is_pow2, ref_is_internal, roundup_pow2
@@ -148,21 +148,6 @@ class DesignValidator(RDLListener):
                     node.inst.inst_src_ref,
                 )
 
-        # Check for unsynthesizable reset
-        reset = node.get_property("reset")
-        if not (reset is None or isinstance(reset, int)):
-            # Has reset that is not a constant value
-            resetsignal = node.get_property("resetsignal")
-            if resetsignal:
-                is_async_reset = resetsignal.get_property("async")
-            else:
-                is_async_reset = self.ds.default_reset_async
-
-            if is_async_reset:
-                self.msg.error(
-                    "A field that uses an asynchronous reset cannot use a dynamic reset value. This is not synthesizable.",
-                    node.inst.inst_src_ref,
-                )
 
     def exit_AddressableComponent(self, node: AddressableNode) -> None:
         if not isinstance(node, RegNode):