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Diffstat (limited to 'control_lib/icache.v')
-rw-r--r-- | control_lib/icache.v | 135 |
1 files changed, 0 insertions, 135 deletions
diff --git a/control_lib/icache.v b/control_lib/icache.v deleted file mode 100644 index bd21f47cc..000000000 --- a/control_lib/icache.v +++ /dev/null @@ -1,135 +0,0 @@ - -module icache - #(parameter AWIDTH=14, - parameter CWIDTH=6) - - (input wb_clk_i, - input wb_rst_i, - input [AWIDTH-1:0] iwb_adr_i, - input iwb_stb_i, - output [31:0] iwb_dat_o, - output iwb_ack_o, - input [31:0] iram_dat_i, - output [AWIDTH-1:0] iram_adr_o, - output iram_en_o, - input flush); - - localparam TAGWIDTH = AWIDTH-CWIDTH-2; - reg stb_d1, ack_d1, miss_d1; - reg [AWIDTH-1:0] held_addr; - reg [31:0] idata [0:(1<<CWIDTH)-1]; - reg [TAGWIDTH-1:0] itags [0:(1<<CWIDTH)-1]; - reg ivalid [0:(1<<CWIDTH)-1]; - - wire [CWIDTH-1:0] rd_line, wr_line; - wire [TAGWIDTH-1:0] wr_tags; - wire store_in_cache; - - // ///////////////////////////////////// - // Write into cache - integer i; - always @(posedge wb_clk_i) - if(wb_rst_i | flush) - for(i=0;i<(1<<CWIDTH);i=i+1) - ivalid[i] <= 0; - else - if(store_in_cache) - ivalid[wr_line] <= 1'b1; - - always @(posedge wb_clk_i) - if(store_in_cache) - begin - idata[wr_line] <= iram_dat_i; - itags[wr_line] <= wr_tags; - end - - // ////////////////////////////////////// - // Read from Cache - wire [TAGWIDTH-1:0] tag_out = itags[rd_line]; - wire valid_out = ivalid[rd_line]; - wire [31:0] data_out = idata[rd_line]; - wire cache_hit = valid_out & (tag_out == iwb_adr_i[AWIDTH-1:CWIDTH+2]); - wire cache_miss = ~cache_hit; - - // ////////////////////////////////////// - // Handle 1-cycle delay of Block-RAM - always @(posedge wb_clk_i) - if(wb_rst_i) - stb_d1 <= 0; - else - stb_d1 <= iwb_stb_i; - - always @(posedge wb_clk_i) - if(wb_rst_i) - held_addr <= 0; - else - held_addr <= iwb_adr_i; - - always @(posedge wb_clk_i) - if(wb_rst_i) - ack_d1 <= 1'b0; - else - ack_d1 <= iwb_ack_o; - - always @(posedge wb_clk_i) - if(wb_rst_i) - miss_d1 <= 0; - else - miss_d1 <= cache_miss; - -//`define IC_NOCACHE -//`define IC_BASIC -//`define IC_FORWARDING_DP -`define IC_FORWARDING_SP -//`define IC_PREFETCH - -`ifdef IC_NOCACHE - assign iwb_dat_o = iram_dat_i; - assign iwb_ack_o = iwb_stb_i & (stb_d1 & ~ack_d1); - assign iram_adr_o = iwb_adr_i; - assign iram_en_o = 1'b1; - assign rd_line = 0; - assign wr_line = 0; - assign wr_tags = 0; - assign store_in_cache = 0; -`endif - -`ifdef IC_BASIC // Very basic, no forwarding, 2 wait states on miss - assign iwb_dat_o = data_out; - assign iwb_ack_o = iwb_stb_i & cache_hit; - assign iram_adr_o = iwb_adr_i; - assign iram_en_o = 1'b1; - assign rd_line = iwb_adr_i[CWIDTH+1:2]; - assign wr_line = rd_line; - assign wr_tags = iwb_adr_i[AWIDTH-1:CWIDTH+2]; - assign store_in_cache = stb_d1 & miss_d1; -`endif - -`ifdef IC_FORWARDING_DP // Simple forwarding, 1 wait state on miss, dual-port ram - assign iwb_dat_o = cache_hit ? data_out : iram_dat_i; - assign iwb_ack_o = iwb_stb_i & (cache_hit | (stb_d1 & ~ack_d1)); - assign iram_adr_o = iwb_adr_i; - assign iram_en_o = 1'b1; - assign rd_line = iwb_adr_i[CWIDTH+1:2]; - assign wr_line = held_addr[CWIDTH+1:2]; - assign wr_tags = held_addr[AWIDTH-1:CWIDTH+2]; - assign store_in_cache = iwb_stb_i & stb_d1 & miss_d1 & ~ack_d1; -`endif - -`ifdef IC_FORWARDING_SP // Simple forwarding, 1 wait state on miss, single-port ram - assign iwb_dat_o = cache_hit ? data_out : iram_dat_i; - assign iwb_ack_o = iwb_stb_i & (cache_hit | (stb_d1 & ~ack_d1)); - assign iram_adr_o = iwb_adr_i; - assign iram_en_o = 1'b1; - assign rd_line = iwb_adr_i[CWIDTH+1:2]; - assign wr_line = rd_line; - assign wr_tags = iwb_adr_i[AWIDTH-1:CWIDTH+2]; - assign store_in_cache = iwb_stb_i & stb_d1 & miss_d1 & ~ack_d1; -`endif - -`ifdef IC_PREFETCH // Forwarding plus prefetch - -`endif - - -endmodule // icache |