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SPxMode m

Sets the clock rate and clock polarity for subsequent SPx and SPiceX transfers. The argument m determines the combination according to the following table:

m

Clock rate (Approx)

Clocks on edge ..

0

1.8MHz

Falling

1

920kHz

Falling

2

230kHz

Falling

3

58kHz

Falling

4

1.8MHz

Rising

5

920kHz

Rising

6 (default)

230kHz

Rising

7

58kHz

Rising

In general, falling edge clocking suits peripherals with a microprocessor and rising edge clocking suits peripherals with hardware shift registers.

This is a low-level instruction associated with the SPLat Expansion Framework. You will most likely never need to know how to use it unless you need to implement systems with more than about 70 I/O points. There is also a tutorial on SPiceX.

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