p2s: Rename input, improve latency

start clock out data right away.

1 files changed, 7 insertions, 7 deletions

diff --git a/par_to_ser.v b/par_to_ser.v
index b3a8eb0..87f9a0e 100644
--- a/par_to_ser.v
+++ b/par_to_ser.v
@@ -1,13 +1,9 @@
 // parallel to serial converter
-// Learning:
-// I think I need a "start" signal (do_send_i),
-// otherwise I'll never know when to copy the input data
-// to out internal register
 
 module par_to_ser (
   input rst_i,
   input clk_i,
-  input do_send_i,
+  input data_valid_i,
   input [7:0] dat_i,
   output reg dat_o
 );
@@ -25,9 +21,13 @@ reg [7:0] send_data = 8'hff;
 always @(posedge clk_i or negedge rst_i) begin
   if (!rst_i) begin
     dat_o <= 1'b1;
-  end else if (do_send_i && !sending) begin
+  end else if (data_valid_i && !sending) begin
     sending <= 1;
-    send_data <= dat_i;
+    dat_o = dat_i[0];
+    send_data[6:0] <= dat_i[7:1];
+  end else if (!data_valid_i) begin
+    sending <= 1'b0;
+    dat_o = 1'b1;
   end else if (sending) begin
     dat_o = send_data[0];
     send_data[6:0] <= send_data[7:1];