input clk,
/* ARM core interface */
- input [31:0] rd_addr,
- input rd_req,
- output reg rd_wait,
- output reg [31:0] rd_data,
+ input [31:0] ic__rd_addr_0a,
+ input ic__rd_req_0a,
+ output wire ic__rd_wait_0a,
+ output wire [31:0] ic__rd_data_1a,
/* bus interface */
- output wire bus_req,
- input bus_ack,
- output reg [31:0] bus_addr,
- input [31:0] bus_rdata,
+ output wire bus_req,
+ input bus_ack,
+ output reg [31:0] bus_addr,
+ input [31:0] bus_rdata,
output wire [31:0] bus_wdata,
- output reg bus_rd,
- output wire bus_wr,
- input bus_ready);
+ output reg bus_rd,
+ output wire bus_wr,
+ input bus_ready);
assign bus_wr = 0;
assign bus_wdata = 0;
+ wire [31:0] rd_addr_0a;
+ wire rd_req_0a;
+ reg rd_wait_0a;
+ reg [31:0] rd_data_1a;
+ assign ic__rd_wait_0a = rd_wait_0a;
+ assign ic__rd_data_1a = rd_data_1a;
+ assign rd_addr_0a = ic__rd_addr_0a;
+ assign rd_req_0a = ic__rd_req_0a;
+
/* [31 tag 10] [9 cache index 6] [5 data index 0]
* so the data index is 6 bits long
* so the cache index is 4 bits long
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
integer i;
initial
cache_tags[i[3:0]] = 0;
end
- wire [5:0] rd_didx = rd_addr[5:0];
- wire [3:0] rd_didx_word = rd_didx[5:2];
- wire [3:0] rd_idx = rd_addr[9:6];
- wire [21:0] rd_tag = rd_addr[31:10];
-
- reg [31:0] prev_rd_addr = 32'hFFFFFFFF;
+ wire [5:0] rd_didx_0a = rd_addr_0a[5:0];
+ wire [3:0] rd_didx_word_0a = rd_didx_0a[5:2];
+ wire [3:0] rd_idx_0a = rd_addr_0a[9:6];
+ wire [21:0] rd_tag_0a = rd_addr_0a[31:10];
- wire cache_hit = cache_valid[rd_idx] && (cache_tags[rd_idx] == rd_tag);
+ reg [31:0] rd_addr_1a = 32'hFFFFFFFF;
- always @(*) begin /* XXX does this work nowadays? */
- rd_wait = rd_req && !cache_hit;
- rd_data = cache_data[rd_idx][rd_didx_word];
- end
+ wire cache_hit_0a = cache_valid[rd_idx_0a] && (cache_tags[rd_idx_0a] == rd_tag_0a);
- reg [3:0] cache_fill_pos = 0;
- assign bus_req = rd_req && !cache_hit; /* xxx, needed for Verilator */
+ reg [3:0] cache_fill_pos_0a = 0;
+ assign bus_req = rd_req_0a && !cache_hit_0a; /* xxx, needed for Verilator */
always @(*)
- if (rd_req && !cache_hit && bus_ack) begin
- bus_addr = {rd_addr[31:6], cache_fill_pos[3:0], 2'b00 /* reads are 32-bits */};
+ if (rd_req_0a && !cache_hit_0a && bus_ack) begin
+ bus_addr = {rd_addr_0a[31:6], cache_fill_pos_0a[3:0], 2'b00 /* reads are 32-bits */};
bus_rd = 1;
end else begin
bus_addr = 0;
bus_rd = 0;
end
+
+ always @(*) begin
+ rd_wait_0a = rd_req_0a && !cache_hit_0a;
+ 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;
- $display("ICACHE: Fill complete for line %x, tag %x", rd_idx, rd_tag);
- end else
- cache_valid[rd_idx] <= 0;
- end
+ // Do the actual read.
+ rd_data_1a <= cache_data[{rd_idx_0a,rd_didx_word_0a}];
+
+ rd_addr_1a <= {rd_addr_0a[31:6], 6'b0};
+ if (cache_fill_pos_0a != 0 && ((rd_addr_1a != {rd_addr_0a[31:6], 6'b0}) || cache_hit_0a)) /* If this wasn't from the same line, or we've moved on somehow, reset the fill circuitry. */
+ cache_fill_pos_0a <= 0;
+ else if (rd_req_0a && !cache_hit_0a && bus_ack && bus_ready) begin
+ $display("ICACHE: FILL: rd addr %08x; bus addr %08x; bus data %08x", rd_addr_0a, bus_addr, bus_rdata);
+ cache_data[{rd_idx_0a,cache_fill_pos_0a}] <= bus_rdata;
+ cache_fill_pos_0a <= cache_fill_pos_0a + 1;
+ if (cache_fill_pos_0a == 15) begin /* Done? */
+ cache_tags[rd_idx_0a] <= rd_tag_0a;
+ cache_valid[rd_idx_0a] <= 1;
+ $display("ICACHE: Fill complete for line %x, tag %x", rd_idx_0a, rd_tag_0a);
+ end else
+ cache_valid[rd_idx_0a] <= 0;
end
end
endmodule
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