always @(posedge clk)
if (rd_req && !cache_hit) begin
if (bus_ready) begin /* Started the fill, and we have data. */
+ $display("CACHE FILL: rq adr %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? */