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-rw-r--r--control_lib/icache.v135
1 files changed, 0 insertions, 135 deletions
diff --git a/control_lib/icache.v b/control_lib/icache.v
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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