Add skeleton of interrupt controller

hw/efinix_fpga/simulation/Makefile

@@ -9,6 +9,8 @@ TEST_PROGRAM_NAME?=loop_test
 TEST_FOLDER?=$(REPO_TOP)/sw/test_code/$(TEST_PROGRAM_NAME)
 TEST_PROGRAM?=$(REPO_TOP)/sw/test_code/$(TEST_PROGRAM_NAME)/$(TEST_PROGRAM_NAME).hex
 
+STANDALONE_TB= interrupt_controller_tb mapper_code_tb
+
 #TODO implement something like sources.list
 
 TOP_MODULE=sim_top
@@ -29,7 +31,7 @@ sim: $(TARGET)
 full_sim: $(TARGET) $(SD_IMAGE)
 	vvp -i $(TARGET) -fst
 
-mapper_tb: $(SRCS) $(TBS)
+$(STANDALONE_TB): $(SRCS) $(TBS)
 	iverilog -g2005-sv $(FLAGS) -s $@ -o $@ $(INC) $(SRCS) $(TBS)
 
 mapper_code_tb: $(SRCS) $(TBS) $(INIT_MEM)

hw/efinix_fpga/simulation/tbs/interrupt_controller_tb.sv

@@ -0,0 +1,93 @@
+`timescale 1ns/1ps
+
+module interrupt_controller_tb();
+
+logic r_clk_cpu;
+
+// clk_cpu
+initial begin
+    r_clk_cpu <= '1;
+    forever begin
+        #125 r_clk_cpu <= ~r_clk_cpu;
+    end
+end
+
+logic reset;
+logic addr;
+logic [7:0] i_data;
+logic [7:0] o_data;
+logic cs;
+logic rwb;
+
+logic [255:0] int_in;
+logic int_out;
+
+interrupt_controller u_interrupt_controller(
+    .clk(r_clk_cpu),
+    .reset(reset),
+    .i_data(i_data),
+    .o_data(o_data),
+    .addr(addr),
+    .cs(cs),
+    .rwb(rwb),
+    .int_in(int_in),
+    .int_out(int_out2)
+);
+
+/* These should be shared */
+task write_reg(input logic [4:0] _addr, input logic [7:0] _data);
+    @(negedge r_clk_cpu);
+    cs <= '1;
+    addr <= _addr;
+    rwb <= '0;
+    i_data <= '1;
+    @(posedge r_clk_cpu);
+    i_data <= _data;
+    @(negedge r_clk_cpu);
+    cs <= '0;
+    rwb <= '1;
+endtask
+
+task read_reg(input logic [2:0] _addr, output logic [7:0] _data);
+    @(negedge r_clk_cpu);
+    cs <= '1;
+    addr <= _addr;
+    rwb <= '1;
+    i_data <= '1;
+    @(posedge r_clk_cpu);
+    _data <= o_data;
+    @(negedge r_clk_cpu);
+    cs <= '0;
+    rwb <= '1;
+endtask
+
+initial begin
+    repeat (5) @(posedge r_clk_cpu);
+    reset = 1;
+    cs = 0;
+    rwb = 1;
+    addr = '0;
+    i_data = '0;
+    int_in = '0;
+    repeat (5) @(posedge r_clk_cpu);
+    reset = 0;
+    repeat (5) @(posedge r_clk_cpu);
+    write_reg(0, 8'h10);
+    write_reg(1, 8'hff);
+    write_reg(0, 8'h20);
+    write_reg(1, 8'hff);
+    repeat (5) @(posedge r_clk_cpu);
+    int_in = 1;
+    @(posedge r_clk_cpu)
+    int_in = 0;
+    repeat (5) @(posedge r_clk_cpu);
+    $finish();
+end
+
+initial
+begin
+    $dumpfile("interrupt_controller_tb.vcd");
+    $dumpvars(0,interrupt_controller_tb);
+end
+
+endmodule

hw/efinix_fpga/src/byte_sel_register.sv

@@ -4,6 +4,7 @@ module byte_sel_register
     parameter ADDR_WIDTH = 32
 )(
     input i_clk,
+    input i_reset,
     input i_write,
     input [$clog2(ADDR_WIDTH)-1:0] i_byte_sel,
     input [DATA_WIDTH-1:0] i_data,
@@ -14,11 +15,16 @@ module byte_sel_register
 logic [DATA_WIDTH*ADDR_WIDTH-1:0] r_data;
 
 assign o_data = r_data[DATA_WIDTH*i_byte_sel +: DATA_WIDTH];
+assign o_full_data = r_data;
 
 always_ff @(posedge i_clk) begin
-    r_data <= r_data;
-    if (i_write) begin
-        r_data[DATA_WIDTH*i_byte_sel +: DATA_WIDTH] <= i_data;
+    if (i_reset) begin
+        r_data <= '0;
+    end else begin
+        r_data <= r_data;
+        if (i_write) begin
+            r_data[DATA_WIDTH*i_byte_sel +: DATA_WIDTH] <= i_data;
+        end
     end
 end
 

hw/efinix_fpga/src/interrupt_controller.sv

@@ -12,6 +12,7 @@ module interrupt_controller
     output logic int_out
 );
 
+logic w_enable_write;
 logic [7:0] w_enable_data;
 logic [255:0] w_enable_full_data;
 
@@ -24,6 +25,7 @@ byte_sel_register #(
     .ADDR_WIDTH(32)
 ) reg_enable (
     .i_clk(clk),
+    .i_reset(reset),
     .i_write(w_enable_write),
     .i_byte_sel(w_byte_sel),
     .i_data(i_data),
@@ -31,10 +33,16 @@ byte_sel_register #(
     .o_full_data(w_enable_full_data)
 );
 
+logic we, re;
+
+assign we = cs & ~rwb;
+assign re = cs & rwb;
+
 logic [255:0] int_masked;
 assign int_masked = int_in & w_enable_full_data;
 
 
+logic w_type_write;
 logic [7:0] w_type_data;
 logic [255:0] w_type_full_data;
 
@@ -43,6 +51,7 @@ byte_sel_register #(
     .ADDR_WIDTH(32)
 ) reg_type (
     .i_clk(clk),
+    .i_reset(reset),
     .i_write(w_type_write),
     .i_byte_sel(w_byte_sel),
     .i_data(i_data),
@@ -50,6 +59,8 @@ byte_sel_register #(
     .o_full_data(w_type_full_data)
 );
 
+logic [7:0] cmd, cmd_next;
+
 logic w_eoi;
 
 logic [255:0] r_int, r_int_next;
@@ -59,10 +70,50 @@ always_comb begin
     if (w_eoi) begin
         r_int_next[irq_val] = 0;
     end
+
+    if (addr == '0 && we) begin
+        cmd_next = i_data;
+    end else begin
+        cmd_next = cmd;
+    end
+
+
+    w_type_write = '0;
+
+    if (addr == '1) begin
+        unique casez (cmd)
+            8'h0?: begin
+                $display("Case 0 not handled");
+            end
+
+            8'h1?: begin
+                w_enable_write = we;
+                w_byte_sel = cmd[3:0];
+                o_data = w_enable_data;
+            end
+
+            8'h2?: begin
+                w_type_write = we;
+                w_byte_sel = cmd[3:0];
+                o_data = w_type_data;
+            end
+
+            8'hff: begin
+                $display("Not handled");
+            end
+        endcase
+    end
+
+    int_out = |r_int;
 end
 
-always_ff @(posedge clk) begin
-    r_int <= r_int_next;
+always_ff @(negedge clk) begin
+    if (reset) begin
+        r_int <= '0;
+    end else begin
+        r_int <= r_int_next;
+        cmd <= cmd_next;
+    end
 end
 
 always_comb begin