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Demonstrate basic interrupt functionality

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This commit is contained in:
Byron Lathi
2023-11-15 08:42:02 -08:00
parent 2b248db94f
commit 40c54e26c0
2 changed files with 20 additions and 13 deletions
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3
hw/efinix_fpga/simulation/tbs/interrupt_controller_tb.sv
View File

@@ -81,6 +81,9 @@ initial begin
@(posedge r_clk_cpu)
int_in = 0;
repeat (5) @(posedge r_clk_cpu);
write_reg(0, 8'hff);
write_reg(1, 8'h01);
repeat (5) @(posedge r_clk_cpu);
$finish();
end

30
hw/efinix_fpga/src/interrupt_controller.sv
View File

@@ -66,10 +66,7 @@ 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
w_eoi = 0;
if (addr == '0 && we) begin
cmd_next = i_data;
@@ -79,6 +76,7 @@ always_comb begin
w_type_write = '0;
w_enable_write = '0;
if (addr == '1) begin
unique casez (cmd)
@@ -99,29 +97,35 @@ always_comb begin
end
8'hff: begin
$display("Not handled");
// Kind of dumb, still requires a data write
w_eoi = i_data[0] & we;
end
endcase
end
int_out = |r_int;
irq_val = 8'hff;
for (int i = 255; i >= 0; i--) begin
if (r_int[i] == 1) begin
irq_val = i;
end
end
r_int_next = (~r_int | w_type_full_data) & int_masked | r_int;
if (w_eoi) begin
r_int_next[irq_val] = 0;
end
end
always_ff @(negedge clk) begin
if (reset) begin
r_int <= '0;
cmd <= '0;
end else begin
r_int <= r_int_next;
cmd <= cmd_next;
end
end
always_comb begin
for (int i = 255; i == 0; i--) begin
if (r_int[i] == 1) begin
irq_val = i;
end
end
end
endmodule