srd: spi: Document output protocol, send CS# changes.

[libsigrokdecode.git] / decoders / spi / __init__.py

diff --git a/decoders/spi/__init__.py b/decoders/spi/__init__.py
index c1b5889fdc28c8c0affc7e4035b2668f8b550114..8734acf3f36ebe57bb468351846ee2a5f97e884e 100644 (file)
--- a/decoders/spi/__init__.py
+++ b/decoders/spi/__init__.py
@@ -23,6 +23,24 @@ Serial Peripheral Interface protocol decoder.
 
 Details:
 TODO
+
+Protocol output format:
+
+SPI packet:
+[<cmd>, <data1>, <data2>]
+
+Commands:
+ - 'DATA': <data1> contains the MISO data, <data2> contains the MOSI data.
+   The data is _usually_ 8 bits (but can also be fewer or more bits).
+   Both data items are Python numbers, not strings.
+ - 'CS CHANGE': <data1> is the old CS# pin value, <data2> is the new value.
+   Both data items are Python numbers (0/1), not strings.
+
+Example:
+ ['CS-CHANGE', 1, 0]
+ ['DATA', 0xff, 0x3a]
+ ['DATA', 0x65, 0x00]
+ ['CS-CHANGE', 0, 1]
 '''
 
 from .spi import *