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| author | Uwe Hermann <uwe@hermann-uwe.de> | 2012-07-11 22:19:31 +0200 |
|---|---|---|
| committer | Uwe Hermann <uwe@hermann-uwe.de> | 2012-07-11 23:13:36 +0200 |
| commit | 2fcd7c22852436c3226de9007e88cb305cce1b00 (patch) | |
| tree | b1681936eec81e3bd91eb43fb395fc2bcf908aba /decoders/spi | |
| parent | b5d3ea69628d49ab5b26e064559f7a237b46c086 (diff) | |
| download | libsigrokdecode-2fcd7c22852436c3226de9007e88cb305cce1b00.tar.gz libsigrokdecode-2fcd7c22852436c3226de9007e88cb305cce1b00.zip | |
srd: Performance improvements for various PDs.
Ignore/skip identical samples in most (low-level) PDs, as we're usually
(but not necessarily always) only interested in pin changes.
This yields a significant performance improvement for the PDs.
The mechanism was already used in the 'i2s', 'jtag', and 'lpc' PDs, but not
yet in all supported low-level decoders. The following PDs now also use
this mechanism: 'dcf77', 'i2c', 'spi', 'uart', and 'usb_signalling'.
Thanks Lars-Peter Clausen <lars@metafoo.de> for bringing this to our
attention.
Diffstat (limited to 'decoders/spi')
| -rw-r--r-- | decoders/spi/spi.py | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/decoders/spi/spi.py b/decoders/spi/spi.py index 2f10ef4..1085786 100644 --- a/decoders/spi/spi.py +++ b/decoders/spi/spi.py @@ -74,6 +74,7 @@ class Decoder(srd.Decoder): self.samplenum = -1 self.cs_was_deasserted_during_data_word = 0 self.oldcs = -1 + self.oldpins = None def start(self, metadata): self.out_proto = self.add(srd.OUTPUT_PROTO, 'spi') @@ -84,7 +85,12 @@ class Decoder(srd.Decoder): def decode(self, ss, es, data): # TODO: Either MISO or MOSI could be optional. CS# is optional. - for (self.samplenum, (miso, mosi, sck, cs)) in data: + for (self.samplenum, pins) in data: + + # Ignore identical samples early on (for performance reasons). + if self.oldpins == pins: + continue + self.oldpins, (miso, mosi, sck, cs) = pins, pins if self.oldcs != cs: # Send all CS# pin value changes. |