Issue: Use wires, since again XST can't always @(cpsr_inflight).

[firearm.git] / DCache.v

diff --git a/DCache.v b/DCache.v
index 098d9e8d4ad0f39089457bb706dd2fc8ca4d4e11..f4dff5a41f1b0d8d12b8a3706c0f0d120fa33643 100644 (file)
--- a/DCache.v
+++ b/DCache.v
@@ -30,8 +30,8 @@ module DCache(
        reg cache_valid [15:0];
        reg [21:0] cache_tags [15:0];
        reg [31:0] cache_data [15:0 /* line */] [15:0 /* word */];
-       
-       reg [4:0] i;
+
+       integer i;      
        initial
                for (i = 0; i < 16; i = i + 1)
                begin
@@ -48,10 +48,11 @@ module DCache(
        
        wire cache_hit = cache_valid[idx] && (cache_tags[idx] == tag);
        
+       wire [31:0] curdata = cache_data[idx][didx_word];
        always @(*) begin
                rw_wait = (rd_req && !cache_hit) || (wr_req && (!bus_ack || !bus_ready));
-               rd_data = cache_data[idx][didx_word];
-               if (!rw_wait)
+               rd_data = curdata;
+               if (!rw_wait && rd_req)
                        $display("DCACHE: READ COMPLETE: Addr %08x, data %08x", addr, rd_data);
        end
        
@@ -67,7 +68,7 @@ module DCache(
                        bus_addr = {addr[31:6], cache_fill_pos[3:0], 2'b00 /* reads are 32-bits */};
                        bus_rd = 1;
                end else if (wr_req && bus_ack) begin
-                       $display("DCACHE: WRITE REQUEST: Addr %08x, data %08x", addr, wr_data);
+                       $display("DCACHE: WRITE REQUEST: Addr %08x, data %08x, wait %d", addr, wr_data, rw_wait);
                        bus_addr = addr;
                        bus_wr = 1;
                        bus_wdata = wr_data;
@@ -79,15 +80,17 @@ module DCache(
                if (rd_req && (cache_fill_pos != 0) && ((prev_addr != {addr[31:6], 6'b0}) || cache_hit))        /* If this wasn't from the same line, or we've moved on somehow, reset the fill circuitry. */
                        cache_fill_pos <= 0;
                else if (rd_req && !cache_hit) begin
-                       if (bus_ready) begin    /* Started the fill, and we have data. */
+                       if (bus_ready && bus_ack) begin /* Started the fill, and we have data. */
+                               $display("DCACHE: FILL: rd addr %08x; bus addr %08x; bus data %08x, bus_req %d, bus_ack %d", addr, bus_addr, bus_rdata, bus_req, bus_ack);
                                cache_data[idx][cache_fill_pos] <= bus_rdata;
                                cache_fill_pos <= cache_fill_pos + 1;
                                if (cache_fill_pos == 15) begin /* Done? */
                                        cache_tags[idx] <= tag;
                                        cache_valid[idx] <= 1;
-                               end
+                               end else
+                                       cache_valid[idx] <= 0;
                        end
                end else if (wr_req && cache_hit)
-                       cache_data[idx][addr[5:2]] = wr_data;
+                       cache_data[idx][addr[5:2]] <= wr_data;
        end
 endmodule