From fe6c9b0f837a3beab3f8c9da2a066a0dbaac959e Mon Sep 17 00:00:00 2001
From: Olof Kindgren <olof.kindgren@gmail.com>
Date: Wed, 6 Jan 2021 22:19:40 +0100
Subject: [PATCH] Optimize bufreg lsb signal and clean up bufreg interface

---
 rtl/serv_bufreg.v | 20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/rtl/serv_bufreg.v b/rtl/serv_bufreg.v
index e9ac7e4..2020dc2 100644
--- a/rtl/serv_bufreg.v
+++ b/rtl/serv_bufreg.v
@@ -1,18 +1,22 @@
 module serv_bufreg
   (
    input wire 	      i_clk,
+   //State
    input wire 	      i_cnt0,
    input wire 	      i_cnt1,
    input wire 	      i_en,
    input wire 	      i_init,
-   input wire 	      i_rs1,
+   output reg [1:0]   o_lsb,
+   //Control
    input wire 	      i_rs1_en,
-   input wire 	      i_imm,
    input wire 	      i_imm_en,
    input wire 	      i_clr_lsb,
-   output reg [1:0]   o_lsb,
-   output wire [31:0] o_dbus_adr,
-   output wire 	      o_q);
+   //Data
+   input wire 	      i_rs1,
+   input wire 	      i_imm,
+   output wire 	      o_q,
+   //External
+   output wire [31:0] o_dbus_adr);
 
    wire 	      c, q;
    reg 		      c_r;
@@ -29,10 +33,8 @@ module serv_bufreg
       if (i_en)
 	data <= {i_init ? q : o_q, data[31:1]};
 
-      if (i_cnt0 & i_init)
-	o_lsb[0] <= q;
-      if (i_cnt1 & i_init)
-	o_lsb[1] <= q;
+      if ((i_cnt0 | i_cnt1) & i_init)
+	o_lsb <= {q,o_lsb[1]};
    end
 
    assign o_q = data[0];