Interface an 8-bit serial device using SPI. The control pin is interfaced to PT2, and the clock and data signals are connected to the SPI. The control and clock signals are normally high. The SPI needs to clock data out on the falling edge of the clock. The clock and data are created by the real SPI, and the control signal is bit-banged. The maximum clock frequency is 1 MHz.
a) Write a function that initializes the interface.
b) Write a function that outputs (transmits) one byte using the SPI port. First send eight bits of data, then make PT2 low, then make PT2 high again.