From 61ca3043840ce6703cf7ab99b637c37108bd9c7b Mon Sep 17 00:00:00 2001
From: Zack Buhman <zack@buhman.org>
Date: Thu, 24 Aug 2023 19:35:47 +0000
Subject: [PATCH] README: add notes on DMA1

---
 README.rst | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/README.rst b/README.rst
index b55561d..040291b 100644
--- a/README.rst
+++ b/README.rst
@@ -133,7 +133,7 @@ the increment added an offset of RA0/WA0 after each bus transfer:
 
    * - mnemonic
      - D0 → [RAM]
-     - [RAM] →D0
+     - [RAM] → D0
    * - DMA0
      - 0 bytes
      - 0 bytes
@@ -162,6 +162,22 @@ the increment added an offset of RA0/WA0 after each bus transfer:
 Note that the DMA transfer length is always decremented by 1 after 4 bytes are
 transferred, regardless of the size of the bus transfer.
 
+Note that selecting DMA1 on a 4-byte bus does not generate misaligned
+writes; instead, the following happens:
+
+.. code:: c
+
+   uint32_t src[] = { 1, 2, 3, 4, ... };
+   extern uint32_t dst[];
+   
+   dst[0] = src[0];
+   dst[0] = src[1];
+   dst[1] = src[2];
+   dst[1] = src[3];
+   ...
+
+   // dst = { 1, 1, 3, 3, ... };
+
 The SCU manual (ST-97-R5-072694) contains this contradictory text:
 
    Only add numbers 0 and 1 are valid for the A-Bus and the write unit is