X-Git-Url: http://git.joshuawise.com/firearm.git/blobdiff_plain/52fd78ff62b919c5dd5e59af2550e4ff733816a1..8744c23dbf6a3c38649c800ae3d96e7e465e01fb:/DCache.v?ds=sidebyside diff --git a/DCache.v b/DCache.v index edfcde1..6ec26a7 100644 --- a/DCache.v +++ b/DCache.v @@ -29,9 +29,9 @@ 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; + reg [31:0] cache_data [255:0 /* {line,word} */]; + + integer i; initial for (i = 0; i < 16; i = i + 1) begin @@ -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 @@ -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, wait %d", addr, wr_data, rw_wait); + $display("DCACHE: WRITE REQUEST: Addr %08x, data %08x", addr, wr_data); bus_addr = addr; bus_wr = 1; bus_wdata = wr_data; @@ -78,16 +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. */ - 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 - 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