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`include "util.svh"
module ntoa
#( BITS = 8
, BASE = 10
, BASE_BITS = $clog2(BASE)
, DIGITS = 3 // should be ceil[log(2**BITS) base BASE] which is hard to do in Verilog :-(
)
( input bit clk
, input bit reset
, output bit n_ready
, input bit n_valid `define n_valid `past(n_valid)
, input bit [BITS-1:0] n_data `define n_data `past(n_data)
, input bit a_ready `define a_ready `past(a_ready)
, output bit a_valid
, output bit [7:0] a_data
);
bit bcd_ready;
bit bcd_valid;
bit [DIGITS-1:0][BASE_BITS-1:0] bcd_data;
bin2bcd
#( .BITS(BITS)
, .BASE(BASE)
, .BASE_BITS(BASE_BITS)
, .DIGITS(DIGITS)
) b2b
( .clk(clk)
, .reset(reset)
, .bin_ready(n_ready)
, .bin_valid(n_valid)
, .bin_data(n_data)
, .bcd_ready(bcd_ready)
, .bcd_valid(bcd_valid) `define bcd_valid `past(bcd_valid)
, .bcd_data(bcd_data) `define bcd_data `past(bcd_data)
);
bit bcd_b_valid;
bit [DIGITS-1:0][BASE_BITS-1:0] bcd_b_data;
bit [$clog2(DIGITS):0] work;
always_ff @(posedge clk) begin
if (reset) begin
a_valid = 0;
bcd_ready = 0;
bcd_b_valid = 0;
end else begin
if (bcd_ready && `bcd_valid) begin
bcd_b_valid = 1;
bcd_b_data = `bcd_data;
// verilator lint_off WIDTH
work = DIGITS;
// verilator lint_on WIDTH
for (int i = 0; i < DIGITS - 1; ++i) begin
if (bcd_b_data[DIGITS-1] != 0) break;
bcd_b_data = { bcd_b_data[DIGITS-2:0], {BASE_BITS{1'b0}} };
--work;
end
end
if (`a_ready) a_valid = 0;
if (!a_valid && bcd_b_valid) begin
if (work != 0) begin
a_valid = 1;
// verilator lint_off WIDTH
if (bcd_b_data[DIGITS-1] < 10)
a_data = "0" + bcd_b_data[DIGITS-1];
else
a_data = "a" + bcd_b_data[DIGITS-1] - 10;
// verilator lint_off WIDTH
bcd_b_data = { bcd_b_data[DIGITS-2:0], {BASE_BITS{1'b0}} };
--work;
end else begin
a_valid = 1;
a_data = ",";
bcd_b_valid = 0;
end
end
bcd_ready = !bcd_b_valid;
end
end
endmodule
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