U2C_RESULT U2C_SpiWriteSS (
            HANDLE hDevice,
             BYTE *pOutBuffer,
             WORD Length,
             ULONG IoNumber,
             BOOL ActiveHigh
);

The U2C_SpiWriteSS function shifts out (writes) a stream of bytes to the SPI slave device.

In contrast to U2C_SpiWrite() function, U2C_SpiWriteSS also selects the SPI slave device to communicate with. Slave Select pin should be preconfigured with U2C_SpiConfigSS() function. You can configure any number of pins for Slave Select signal and specify different pins for each SPI transaction.

Use U2C_SpiWrite() function if you don't want to involve slave device selection into SPI transaction. This can be useful if you want to send several buffers through SPI Bus changing Slave Select pin only once. You can use GPIO routines to work with Slave Select pin in such a case.

Parameters:

	hDevice	Handle to the U2C-12 device.
	pOutBuffer	Pointer to the buffer containing the data to be shifted out to the SPI slave device.
	Length	Number of bytes to be shifted out to the SPI slave device.
	IoNumber	GPIO pin to be used for SPI slave device selection. Numbers 0..7 correspond to Port A pins 0..7 Numbers 8..15 correspond to Port B pins 0..7 Number 16..23 correspond to Port C pins 0..7
	ActiveHigh	This parameter determines the active state of the Slave Select pin (state during the SPI transfer). If ActiveHigh is TRUE - Slave Select pin value will be changed from logical "0" to logical "1" before SPI transaction and returned back to logical "0" after the data is transmitted. If ActiveHigh is FALSE - Slave Select pin value will be changed from logical "1" to logical "0" before SPI transaction and returned back to logical "1" after the data is transmitted.

Return values:

	U2C_SUCCESS	The data was successfully written to the SPI slave device.
	U2C_HARDWARE_NOT_FOUND	U2C-12 device referenced by hDevice handle was not found.
	U2C_BAD_PARAMETER	IoNumber is out of range.