X-Git-Url: http://git.joshuawise.com/firearm.git/blobdiff_plain/52fd78ff62b919c5dd5e59af2550e4ff733816a1..2b5c79c05898ff20b0c04cd78bccb2580f6c8331:/ICache.v diff --git a/ICache.v b/ICache.v index b9e4eff..8b9eac3 100644 --- a/ICache.v +++ b/ICache.v @@ -30,9 +30,9 @@ module ICache( 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} */]; //synthesis attribute ram_style of cache_data is distributed - reg [4:0] i; + integer i; initial for (i = 0; i < 16; i = i + 1) begin @@ -49,11 +49,6 @@ module ICache( wire cache_hit = cache_valid[rd_idx] && (cache_tags[rd_idx] == rd_tag); - always @(*) begin /* XXX does this work nowadays? */ - rd_wait = rd_req && !cache_hit; - rd_data = cache_data[rd_idx][rd_didx_word]; - end - reg [3:0] cache_fill_pos = 0; assign bus_req = rd_req && !cache_hit; /* xxx, needed for Verilator */ always @(*) @@ -64,21 +59,27 @@ module ICache( bus_addr = 0; bus_rd = 0; end + + wire [31:0] curdata = cache_data[{rd_idx,rd_didx_word}]; + always @(*) begin + rd_wait = rd_req && !cache_hit; + rd_data = curdata; + end always @(posedge clk) begin prev_rd_addr <= {rd_addr[31:6], 6'b0}; if (cache_fill_pos != 0 && ((prev_rd_addr != {rd_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_ack && bus_ready) begin /* Started the fill, and we have data. */ - $display("ICACHE: FILL: rd addr %08x; bus addr %08x; bus data %08x", rd_addr, bus_addr, bus_rdata); - cache_data[rd_idx][cache_fill_pos] <= bus_rdata; - cache_fill_pos <= cache_fill_pos + 1; - if (cache_fill_pos == 15) begin /* Done? */ - cache_tags[rd_idx] <= rd_tag; - cache_valid[rd_idx] <= 1; - end - end + else if (rd_req && !cache_hit && bus_ack && bus_ready) begin + $display("ICACHE: FILL: rd addr %08x; bus addr %08x; bus data %08x", rd_addr, bus_addr, bus_rdata); + cache_data[{rd_idx,cache_fill_pos}] <= bus_rdata; + cache_fill_pos <= cache_fill_pos + 1; + if (cache_fill_pos == 15) begin /* Done? */ + cache_tags[rd_idx] <= rd_tag; + cache_valid[rd_idx] <= 1; + $display("ICACHE: Fill complete for line %x, tag %x", rd_idx, rd_tag); + end else + cache_valid[rd_idx] <= 0; end end endmodule