Differences

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--- spi [ 04.02.2025 18:16] – created lars
+++ spi [ 05.02.2025 01:31] (current) – lars
@@ Line 2: / Line 2: @@
 Different variants exist. Usually SPI refers to the Motorola Serial Peripheral Interface. Other variants are the Texas Instruments Serial protocol (SSP) and the National Instruments Microwire.
+===== Protocol =====
+Most significant bit first
@@ Line 23: / Line 27: @@
   - data bits are read when clock goes to idle level.
-^ mode ^ CPOL ^ CPHA ^ write bit ^ read bit ^
+^ mode ^ CPOL ^ CPHA ^ write bit                               ^ read bit        ^
-| 0 | 0 | 0 | falling clock, and when /CS activates | rising clock  |
+| 0    | 0    | 0    | clock goes low, and when /CS activates  | clock goes high |
-| 1 | 0 | 1 | rising clock                          | falling clock |
+| 1    | 0    | 1    | clock goes high                         | clock goes low  |
-| 2 | 1 | 0 | rising clock, and when /CS activates  | falling clock |
+| 2    | 1    | 0    | clock goes high, and when /CS activates | clock goes low  |
-| 3 | 1 | 1 | falling clock                         | rising clock  |
+| 3    | 1    | 1    | clock goes low                          | clock goes high |
@@ Line 33: / Line 37: @@
 The part "signal_name" in the described functions will be replaced by the name of the signal. E.g. if your signal is called "audio" then the API function "signal_name_transfer" will become "audio_transfer".
-<code>void signal_name_transfer(const uint8_t *data_send, const uint8_t *data_receive, const uint32_t length)</code>
+<code>
+void signal_name_transfer(const uint8_t *data_send,
+                          const uint8_t *data_receive,
+                          const uint32_t length )</code>
 Will send "length" bytes from the buffer "data_send" out on MOSI and will receive the same amount of bytes from MISO into the buffer "data_receive".