Programming 8-bit PIC Microcontrollers in C

3.5. PIC16 C SPI Serial Bus

• SPI system connections

• SPI function set

• SPI test system

The serial peripheral interface master controller uses hardware slave selection to identify a peripheral device with which it wishes to exchange data (refer to Section 1.4 for full details of the signaling protocol). The available set of SPI driver functions are shown in Table 3.7

Table 3.7. SPI Function Set

Operation	Description	Example
SPI SETUP	Initializes SPI serial port	setup_spi(spi_master);
SPI READ	Receives data byte from SPI port	inbyte=spi_read();
SPI WRITE	Sends data byte via SPI port	spi_write(outbyte);
SPI TRANSFER	Sends and receives via SPI	inbyte=spi_xfer(outbyte);
SPI RECEIVED	Checks if SPI data received	done=spi_data_is_in();

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The test system has a slave transmitter ...