Memory: Move all bus control logic to its own always block.

[firearm.git] / DCache.v

diff --git a/DCache.v b/DCache.v
index ccaa6b1f5b871429e10d658200556b40ee38937a..aec6ae66399fe4786398de6579dc9c383d68fa7e 100644 (file)
--- a/DCache.v
+++ b/DCache.v
@@ -29,7 +29,7 @@ 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 [31:0] cache_data [255:0 /* {line,word} */];
 
        integer i;      
        initial
@@ -48,9 +48,10 @@ 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];
+               rd_data = curdata;
                if (!rw_wait && rd_req)
                        $display("DCACHE: READ COMPLETE: Addr %08x, data %08x", addr, rd_data);
        end
@@ -78,18 +79,18 @@ module DCache(
                prev_addr <= {addr[31:6], 6'b0};
                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 && 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 else
-                                       cache_valid[idx] <= 0;
-                       end
-               end else if (wr_req && cache_hit)
-                       cache_data[idx][addr[5:2]] = wr_data;
+               else if (rd_req && !cache_hit && 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_fill_pos <= cache_fill_pos + 1;
+                       if (cache_fill_pos == 15) begin /* Done? */
+                               cache_tags[idx] <= tag;
+                               cache_valid[idx] <= 1;
+                       end else
+                               cache_valid[idx] <= 0;
+               end
+               
+               /* Split this out because XST is kind of silly about this sort of thing. */
+               if ((rd_req && !cache_hit && bus_ready && bus_ack) || (wr_req && cache_hit))
+                       cache_data[wr_req ? {idx,addr[5:2]} : {idx,cache_fill_pos}] <= wr_req ? wr_data : bus_rdata;
        end
 endmodule