Serial Peripheral Interface Module (SPI)
Technical Data MC68HC908AB32 — Rev. 1.0
304 Serial Peripheral Interface Module (SPI) MOTOROLA
16.14 I/O Registers
Three registers control and monitor SPI operation:
• SPI control register (SPCR)
• SPI status and control register (SPSCR)
• SPI data register (SPDR)
16.14.1 SPI Control Register
The SPI control register:
• Enables SPI module interrupt requests
• Configures the SPI module as master or slave
• Selects serial clock polarity and phase
• Configures the SPSCK, MOSI, and MISO pins as open-drain
outputs
• Enables the SPI module
SPRIE — SPI Receiver Interrupt Enable Bit
This read/write bit enables CPU interrupt requests generated by the
SPRF bit. The SPRF bit is set when a byte transfers from the shift
register to the receive data register. Reset clears the SPRIE bit.
1 = SPRF CPU interrupt requests enabled
0 = SPRF CPU interrupt requests disabled
Address: $0010
Bit 7 654321Bit 0
Read:
SPRIE R SPMSTR CPOL CPHA SPWOM SPE SPTIE
Write:
Reset: 00101000
= Unimplemented
R
= Reserved
Figure 16-13. SPI Control Register (SPCR)