Init SPI	
	Enable clock to GPIO Port A
	Enable the clock to the SSI module
	Wait for the SSI module to be ready
	Program the GPIO to use alternate functions for SSI pins (PA2/3/4/5)
	Map SSI to those pins. This is a mux value of 2 that we
	     want to use for specifying the function on bits 2, 3, 4, & 5
	Enable PA2, 3, 4, and 5 as digital pins
	Enable PA2, 3, and 5 as outputs
	Enable PA4 as an input
	Enable pull up resitor for clock line (PA2)
	Wait for the SSI0 module to be ready
	Disable SSI before programming mode bits
	Select Master mode (MS) and TXIS indicating end of transmit
	Configure SSI clock source to the system clock
	Configure clock prescaler
	Configure clock rate (SCR), phase and polarity (SPH, SPO), mode (FRF), data size (DSS)
	Locally enable interrupts(TXIM in SSIIM) 
	Enable SSI module 
	Globally enable interrupts
	Enable NVIC interrupt for SSI when starting to transmit

SendCommand
	Write data to register
	Unmask the EOT interrupt

ReadData
	Read from data register

EOT ISR
	Mask the EOT interrupt
	Post EOT event to CommService