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rewrite of id_tracking

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Eric Matthews 2019-09-02 15:57:28 -07:00
parent 2ae42cc9eb
commit 3717214b56
1 changed files with 13 additions and 40 deletions
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53
core/id_tracking.sv
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@ -35,14 +35,11 @@ module id_tracking
output logic empty
);
//////////////////////////////////////////
localparam INUSE_COUNTER_W = $clog2(MAX_INFLIGHT_COUNT+1);
localparam MAX_INFLIGHT_COUNT_W = $clog2(MAX_INFLIGHT_COUNT+1);
logic [INUSE_COUNTER_W-1:0] inuse_index;
instruction_id_t inuse_ids [MAX_INFLIGHT_COUNT-1:0];
logic [MAX_INFLIGHT_COUNT_W-1:0] in_use_index;
logic [MAX_INFLIGHT_COUNT_W-1:0] available_index;
instruction_id_t in_use_ids [MAX_INFLIGHT_COUNT-1:0];
instruction_id_t available_ids [MAX_INFLIGHT_COUNT-1:0];
genvar i;
////////////////////////////////////////////////////
//Implementation
@ -50,61 +47,37 @@ module id_tracking
//Initial ordering, FIFO has no reset, as ID ordering is arbitrary
initial begin
for (int i=0; i<MAX_INFLIGHT_COUNT; i++) begin
available_ids[i] = i[$clog2(MAX_INFLIGHT_COUNT)-1:0];
inuse_ids[i] = i[$clog2(MAX_INFLIGHT_COUNT)-1:0];
end
end
//On first write will roll over to [1,00...0]
//Upper bit indicates is the valid signal
always_ff @ (posedge clk) begin
if (rst) begin
in_use_index[MAX_INFLIGHT_COUNT_W-1] <= 0;
in_use_index[MAX_INFLIGHT_COUNT_W-2:0] <= '1;
end else
in_use_index <= in_use_index + MAX_INFLIGHT_COUNT_W'(issued) - MAX_INFLIGHT_COUNT_W'(retired);
end
//Available FIFO starts full
//Upper bit is id_available
always_ff @ (posedge clk) begin
if (rst)
available_index[MAX_INFLIGHT_COUNT_W-1:0] <= '1;
inuse_index <= '1;
else
available_index <= available_index + MAX_INFLIGHT_COUNT_W'(retired) - MAX_INFLIGHT_COUNT_W'(issued);
inuse_index <= inuse_index + INUSE_COUNTER_W'(retired) - INUSE_COUNTER_W'(issued);
end
assign empty = ~in_use_index[MAX_INFLIGHT_COUNT_W-1];
assign id_available = available_index[MAX_INFLIGHT_COUNT_W-1];
assign empty = &inuse_index;//all ones
assign id_available = inuse_index[INUSE_COUNTER_W-1];
always_ff @ (posedge clk) begin
if (issued)
in_use_ids[0] <= next_id;
end
generate
for (i=1 ; i < MAX_INFLIGHT_COUNT; i++) begin
always_ff @ (posedge clk) begin
if (issued)
in_use_ids[i] <= in_use_ids[i-1];
end
end
endgenerate
assign next_id = inuse_ids[inuse_index[INUSE_COUNTER_W-2:0]];
assign oldest_id = inuse_ids[MAX_INFLIGHT_COUNT-1];
always_ff @ (posedge clk) begin
if (retired)
available_ids[0] <= oldest_id;
inuse_ids[0] <= inuse_ids[MAX_INFLIGHT_COUNT-1];
end
generate
for (i=1 ; i < MAX_INFLIGHT_COUNT; i++) begin
always_ff @ (posedge clk) begin
if (retired)
available_ids[i] <= available_ids[i-1];
inuse_ids[i] <= inuse_ids[i-1];
end
end
endgenerate
assign next_id = available_ids[available_index[MAX_INFLIGHT_COUNT_W-2:0]];
assign oldest_id = in_use_ids[in_use_index[MAX_INFLIGHT_COUNT_W-2:0]];
////////////////////////////////////////////////////
//End of Implementation
////////////////////////////////////////////////////