From 28d7b77b927144d69a82d8eaec6dc65c8afc5626 Mon Sep 17 00:00:00 2001
From: Julian Blake Kongslie
Date: Sun, 29 May 2022 16:33:24 -0700
Subject: Only run selector logic if we need a new selection next cycle.

---
 hdl/mem_arbiter.sv | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

(limited to 'hdl')

diff --git a/hdl/mem_arbiter.sv b/hdl/mem_arbiter.sv
index 1404a54..e39317d 100644
--- a/hdl/mem_arbiter.sv
+++ b/hdl/mem_arbiter.sv
@@ -32,12 +32,15 @@ module mem_arbiter
                 hold_valid[i] = 0;
             selector = 0;
         end else begin
+            automatic bit selector_stale = 0;
+
             if (ram_ready) ram_valid = 0;
 
             if (!ram_valid && hold_valid[selector]) begin
                 ram_valid = 1;
                 ram_data = hold_data[selector];
                 hold_valid[selector] = 0;
+                selector_stale = 1;
             end
 
             if (hold_valid == 0) begin
@@ -59,7 +62,7 @@ module mem_arbiter
                 end
             end
 
-            if (hold_valid != 0) begin
+            if (hold_valid != 0 && (selector_stale || !ram_valid)) begin
                 for (int i = 0; i < `NUM_PDPS+1; ++i) begin
                     automatic int j = selector + i;
                     if (j > `NUM_PDPS)
-- 
cgit v1.2.3