rv32g-core

commit e47093efc32ef69a2bdc66a837d437e1958bd158
parent 364ec7627b3932d642f2b4bf813b7493e721ed1e
Author: Vineet Kumar <git@vineetk.net>
Date:   Sat, 11 Jul 2026 18:30:16 +0530

make unified memory have registered reads again

Diffstat:
M
rtl/unified_memory.sv
 | 
15
++++++---------

1 file changed, 6 insertions(+), 9 deletions(-)
diff --git a/rtl/unified_memory.sv b/rtl/unified_memory.sv
@@ -23,18 +23,15 @@ module unified_memory
    always_comb begin
      imem_idx = (imem_addr - BASE_ADDR) >> 2;
      dmem_idx = (dmem_addr - BASE_ADDR) >> 2;
-
-     imem_data = (imem_idx < CACHE_DEPTH) ? mem[imem_idx] : '0;
-     imem_valid = (imem_idx < CACHE_DEPTH) ? 1'b1 : 1'b0;
-
-     // TODO switch back to registered read once pipelined.
-     // single-cycle hart requires combinational same-cycle read.
-     // otherwise it causes tests like rv32ui-p-fence_i to fail.
-     dmem_rdata = (dmem_idx < CACHE_DEPTH) ? mem[dmem_idx] : '0;
-     dmem_valid = (dmem_idx < CACHE_DEPTH) ? 1'b1 : 1'b0;
    end
 
    always_ff @(posedge clk) begin
+     imem_valid <= (imem_idx < CACHE_DEPTH) ? 1'b1 : 1'b0;
+     dmem_valid <= (dmem_idx < CACHE_DEPTH) ? 1'b1 : 1'b0;
+
+     imem_data <= (imem_idx < CACHE_DEPTH) ? mem[imem_idx] : '0;
+     dmem_rdata <= (dmem_idx < CACHE_DEPTH) ? mem[dmem_idx] : '0;
+
      // for self-modifying memory
      if (dmem_we && dmem_idx < CACHE_DEPTH) begin
        for (int b = 0; b < 4; b++) begin