44 lines
1.7 KiB
Markdown
44 lines
1.7 KiB
Markdown
# spi Format
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Set the Serial Peripheral Interface (SPI) format.
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```sig
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pins.spiFormat(8, 3);
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```
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The data sent over a SPI connection has a number of _bits_ to represent each value. Also, position of the clock signal (SCK), ``high`` or ``low``, and the exact time when a data value is read is determined by the SPI _mode_. Both the bits and mode values together are called the _SPI format_.
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### ~ hint
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**Simulator**: This function needs real hardware to work with. It's not supported in the simulator.
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### ~
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The default number of bits is `8` and the default mode value is `3`.
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## Parameters
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* **bits**: the [number](types/number) of bits for each data value sent and received on the SPI connection. This value must be ``8`` since only 8 bits is currently supported for SPI data values.
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* **mode**: a [number](/types/number) that is the mode value for the SPI clock (**SCK**) signalling. The different modes are:
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>* `0`: the data line is active when **SCK** goes to ``high`` and the data values are read when **SCK** goes to ``high``
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>* `1`: the data line is active when **SCK** goes to ``high`` and the data values are read when **SCK** goes to ``low``
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>* `2`: the data line is active when **SCK** goes to ``low`` and the data values are read when **SCK** goes to ``high``
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>* `3`: the data line is active when **SCK** goes to ``low`` and the data values are read when **SCK** goes to ``low``
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## Example
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Set the pins and format for the SPI connection.
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```blocks
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pins.spiPins(DigitalPin.P15, DigitalPin.P14, DigitalPin.P13);
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pins.spiFormat(8, 3);
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```
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## See also
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[spi write](/reference/pins/spi-write),
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[spi pins](/reference/pins/spi-pins),
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[spi frequency](/reference/pins/spi-frequency)
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[SPI Programming](https://developer.mbed.org/handbook/SPI)
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