From c3a6c5f8c614919982ef31c9e8e324525ce105b1 Mon Sep 17 00:00:00 2001
From: Alvaro <alvieboy@alvie.com>
Date: Fri, 22 Oct 2010 18:18:33 +0200
Subject: zpu_core_small: load

memAAddr is not being initialized during IO read operations
(LOAD). This might cause spurious writes to invalid addresses,
and invalid values to be loaded onto the stack. This patch
explicitly sets memAAddr to correct value (sp).
---
 zpu/hdl/zpu4/core/zpu_core_small.vhd | 1 +
 1 file changed, 1 insertion(+)

diff --git a/zpu/hdl/zpu4/core/zpu_core_small.vhd b/zpu/hdl/zpu4/core/zpu_core_small.vhd
index f9484bb..681fb09 100644
--- a/zpu/hdl/zpu4/core/zpu_core_small.vhd
+++ b/zpu/hdl/zpu4/core/zpu_core_small.vhd
@@ -494,6 +494,7 @@ begin
 							null; 
 					end case;
 				when State_ReadIO =>
+					memAAddr <= sp;
 					if (in_mem_busy = '0') then
 						state <= State_Fetch;
 						memAWriteEnable <= '1';
-- 
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