X-Git-Url: http://sigrok.org/gitweb/?a=blobdiff_plain;f=decoders%2Fspi%2Fpd.py;h=3bebc7d6efa70e822069eeb5002a47ddc1e31748;hb=9ed115003c754ed2af523af98d22123cee6e99d3;hp=cd40946c791ec5a1fb13edea8fbe6df75ed20e1f;hpb=808c6e7496410ea473c1a625530fd15f779b542e;p=libsigrokdecode.git

diff --git a/decoders/spi/pd.py b/decoders/spi/pd.py
index cd40946..3bebc7d 100644
--- a/decoders/spi/pd.py
+++ b/decoders/spi/pd.py
@@ -266,6 +266,10 @@ class Decoder(srd.Decoder):
             self.have_mosi = (mosi in (0, 1))
             self.have_cs = (cs in (0, 1))
 
+            # Either MISO or MOSI (but not both) can be omitted.
+            if not (self.have_miso or self.have_mosi):
+                raise Exception('Either MISO or MOSI (or both) pins required.')
+
             # State machine.
             if self.state == 'IDLE':
                 self.find_clk_edge(miso, mosi, clk, cs)