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Fix small error in prefetcher where GNT occur one cycle after we wanted

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to prefetch
This commit is contained in:
Andreas Traber 2015-09-23 15:32:30 +02:00
parent 9ceeb15bc8
commit a3256c4df2
1 changed files with 9 additions and 12 deletions
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21
prefetch_L0_buffer.sv
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@ -101,14 +101,6 @@ module prefetch_L0_buffer
always_comb
begin
valid_o = 1'b0;
case(addr_o[3:2])
2'b00: begin unaligned_rdata_o = {L0_buffer[0][15:0], previous_chunk }; unaligned_valid_o = valid_previous_chunk; end
2'b01: begin unaligned_rdata_o = {L0_buffer[1][15:0], L0_buffer[0][31:16] }; unaligned_valid_o = valid_o; end
2'b10: begin unaligned_rdata_o = {L0_buffer[2][15:0], L0_buffer[1][31:16] }; unaligned_valid_o = valid_o; end
2'b11: begin unaligned_rdata_o = {L0_buffer[3][15:0], L0_buffer[2][31:16] }; unaligned_valid_o = valid_o; end
endcase // addr_o
addr_o = current_address + (pointer_cs<<2);
pointer_ns = pointer_cs;
instr_req_o = 1'b0;
@ -117,6 +109,13 @@ module prefetch_L0_buffer
rdata_o = instr_rdata_i[pointer_cs];
clear_buffer = 1'b0;
case(addr_o[3:2])
2'b00: begin unaligned_rdata_o = {L0_buffer[0][15:0], previous_chunk }; unaligned_valid_o = valid_previous_chunk; end
2'b01: begin unaligned_rdata_o = {L0_buffer[1][15:0], L0_buffer[0][31:16] }; unaligned_valid_o = valid_o; end
2'b10: begin unaligned_rdata_o = {L0_buffer[2][15:0], L0_buffer[1][31:16] }; unaligned_valid_o = valid_o; end
2'b11: begin unaligned_rdata_o = {L0_buffer[3][15:0], L0_buffer[2][31:16] }; unaligned_valid_o = valid_o; end
endcase // addr_o
case(CS)
@ -198,12 +197,12 @@ module prefetch_L0_buffer
begin
instr_req_o = 1'b1; //if the cpu is ready to sample the instruction, then ask for a new instruction
instr_addr_o = current_address + 5'h10;
pointer_ns = '0;
update_current_address = 1'b1;
if(instr_gnt_i)
begin
NS = WAIT_RVALID;
pointer_ns = '0;
update_current_address = 1'b1;
end
else
begin
@ -274,8 +273,6 @@ module prefetch_L0_buffer
if(instr_gnt_i)
begin
NS = WAIT_RVALID;
pointer_ns = '0;
update_current_address = 1'b1;
end
else
begin