CCS C Compiler Manual PCB / PCM / PCH

PreProcessor
CLOCK_HIGH=n High time of clock in us (not needed if BAUD= is
used). (default=0)
CLOCK_LOW=n Low time of clock in us (not needed if BAUD= is
used). (default=0)
DI=pin
Optional pin for incoming data.
DO=pin
Optional pin for outgoing data.
CLK=pin
Clock pin.
MODE=n
The mode to put the SPI bus.
ENABLE=pin
Optional pin to be active during data transfer.
LOAD=pin
Optional pin to be pulsed active after data is
transferred.
DIAGNOSTIC=pin Optional pin to the set high when data is sampled.
SAMPLE_RISE
Sample on rising edge.
SAMPLE_FALL Sample on falling edge (default).
BITS=n
Max number of bits in a transfer. (default=32)
SAMPLE_COUNT=n Number of samples to take (uses majority vote).
(default=1
LOAD_ACTIVE=n Active state for LOAD pin (0, 1).
ENABLE_ACTIVE=n Active state for ENABLE pin (0, 1). (default=0)
IDLE=n
Inactive state for CLK pin (0, 1). (default=0)
ENABLE_DELAY=n Time in us to delay after ENABLE is activated.
(default=0)
DATA_HOLD=n Time between data change and clock change
LSB_FIRST
LSB is sent first.
MSB_FIRST
MSB is sent first. (default)
STREAM=id
Specify a stream name for this protocol.
SPI1 Use the hardware pins for SPI Port 1
SPI2 Use the hardware pins for SPI Port 2
FORCE_HW
Use the pic hardware SPI.
NOINIT
Don't initialize the hardware SPI Port
Purpose:
The SPI library contains functions to implement an SPI bus. After setting all of the
proper parameters in #USE SPI, the spi_xfer() function can be used to both
transfer and receive data on the SPI bus.
The SPI1 and SPI2 options will use the SPI hardware onboard the PIC. The most
common pins present on hardware SPI are: DI, DO, and CLK. These pins don’t
need to be assigned values through the options; the compiler will automatically
assign hardware-specific values to these pins. Consult your PIC’s data sheet as to
where the pins for hardware SPI are. If hardware SPI is not used, then software
SPI will be used. Software SPI is much slower than hardware SPI, but software
SPI can use any pins to transfer and receive data other than just the pins tied to
the PIC’s hardware SPI pins.
The MODE option is more or less a quick way to specify how the stream is going
to sample data. MODE=0 sets IDLE=0 and SAMPLE_RISE. MODE=1 sets
IDLE=0 and SAMPLE_FALL. MODE=2 sets IDLE=1 and SAMPLE_FALL.
MODE=3 sets IDLE=1 and SAMPLE_RISE. There are only these 4 MODEs.
SPI cannot use the same pins for DI and DO. If needed, specify two streams: one
to send data and another to receive data.
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