Add beginnings of interrupt controller

hw/efinix_fpga/src/byte_sel_register.sv

@@ -0,0 +1,25 @@
+module byte_sel_register
+#(
+    parameter DATA_WIDTH = 8,
+    parameter ADDR_WIDTH = 32
+)(
+    input i_clk,
+    input i_write,
+    input [$clog2(ADDR_WIDTH)-1:0] i_byte_sel,
+    input [DATA_WIDTH-1:0] i_data,
+    output [DATA_WIDTH-1:0] o_data,
+    output [DATA_WIDTH*ADDR_WIDTH-1:0] o_full_data
+);
+
+logic [DATA_WIDTH*ADDR_WIDTH-1:0] r_data;
+
+assign o_data = r_data[DATA_WIDTH*i_byte_sel +: DATA_WIDTH];
+
+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;
+    end
+end
+
+endmodule

hw/efinix_fpga/src/interrupt_controller.sv

@@ -4,26 +4,72 @@ module interrupt_controller
     input reset,
     input [7:0] i_data,
     output logic [7:0] o_data,
+    input addr,
     input cs,
     input rwb,
 
-    output logic irqb_master,
-
-    input irqb0, irqb1, irqb2, irqb3,
-    input irqb4, irqb5, irqb6, irqb7
+    input [255:0] int_in,
+    output logic int_out
 );
 
+logic [7:0] w_enable_data;
+logic [255:0] w_enable_full_data;
 
-//All of the inputs are low level triggered.
-logic [7:0] irqbv;
-assign irqbv = {irqb0, irqb1, irqb2, irqb3, irqb4, irqb5, irqb6, irqb7};
+logic [4:0] w_byte_sel;
 
-always @(posedge clk) begin
-    o_data <= irqbv;
-    irqb_master = &irqbv;
+logic [7:0] irq_val;
 
-    if (cs & ~rwb) begin
-        o_data <= o_data | i_data;
+byte_sel_register #(
+    .DATA_WIDTH(8),
+    .ADDR_WIDTH(32)
+) reg_enable (
+    .i_clk(clk),
+    .i_write(w_enable_write),
+    .i_byte_sel(w_byte_sel),
+    .i_data(i_data),
+    .o_data(w_enable_data),
+    .o_full_data(w_enable_full_data)
+);
+
+logic [255:0] int_masked;
+assign int_masked = int_in & w_enable_full_data;
+
+
+logic [7:0] w_type_data;
+logic [255:0] w_type_full_data;
+
+byte_sel_register #(
+    .DATA_WIDTH(8),
+    .ADDR_WIDTH(32)
+) reg_type (
+    .i_clk(clk),
+    .i_write(w_type_write),
+    .i_byte_sel(w_byte_sel),
+    .i_data(i_data),
+    .o_data(w_type_data),
+    .o_full_data(w_type_full_data)
+);
+
+logic w_eoi;
+
+logic [255:0] r_int, r_int_next;
+
+always_comb begin
+    r_int_next = (~r_int | w_type_full_data) & int_masked;
+    if (w_eoi) begin
+        r_int_next[irq_val] = 0;
+    end
+end
+
+always_ff @(posedge clk) begin
+    r_int <= r_int_next;
+end
+
+always_comb begin
+    for (int i = 255; i == 0; i--) begin
+        if (r_int[i] == 1) begin
+            irq_val = i;
+        end
     end
 end
 

hw/efinix_fpga/src/super6502.sv

@@ -267,16 +267,7 @@ interrupt_controller u_interrupt_controller(
     .i_data(cpu_data_in),
     .o_data(w_irq_data_out),
     .cs(w_irq_cs),
-    .rwb(cpu_rwb),
-    .irqb_master(cpu_irqb),
-    .irqb0(w_timer_irqb),
-    .irqb1('1),
-    .irqb2('1),
-    .irqb3('1),
-    .irqb4('1),
-    .irqb5('1),
-    .irqb6('1),
-    .irqb7('1)
+    .rwb(cpu_rwb)
 );