Serial Peripheral Interface Module (SPI)
Interrupts
MC68HC908MR16/MC68HC908MR32 — Rev. 4.0 Advance Information
MOTOROLA Serial Peripheral Interface Module (SPI) 263
Figure 13-10. SPI Interrupt Request Generation
The error interrupt enable bit (ERRIE) enables both the MODF and
OVRF bits to generate a receiver/error CPU interrupt request.
The mode fault enable bit (MODFEN) can prevent the MODF flag from
being set so that only the OVRF bit is enabled by the ERRIE bit to
generate receiver/error CPU interrupt requests.
These sources in the SPI status and control register can g enerat e CPU
interrupt requests:
SPI receiver full bit (SPRF) — The SPRF bit becomes set every
time a byte transfers from the shift register to the receive data
register. If the SPI receiver interrupt enable bit, SPRIE, is also set,
SPRF can generate either an SPI receiver/error or CPU interrupt.
SPI transmitter empty (SPTE) — The SPTE bit becomes set every
time a byte transfers from the transmit data register to the shift
register. If the SPI transmit interrupt enable bit, SPTIE, is also se t,
SPTE can generate either an SPTE or CPU interrupt request.
SPTE SPTIE
SPRFSPRIE
ERRIE
MODF
OVRF
SPE
SPI TRANSMITTER
CPU INTERRUPT REQUEST
SPI RECEIVER/ERROR
CPU INTERRUPT REQUEST