Serial Peripheral Interface Module (SPI)
15.7 Interrupts
Four SPI status flags can be enabled to generate CPU interrupt requests as shown
in Table 15-2.
Table 15-2. SPI Interrupts
Flag
Request
SPTE transmitter empty
SPRF receiver full
OVRF overflow
SPI transmitter CPU interrupt request (SPTIE = 1, SPE = 1)
SPI receiver CPU interrupt request (SPRIE = 1)
SPI receiver/error interrupt request (ERRIE = 1)
SPI receiver/error interrupt request (ERRIE = 1)
MODF mode fault
The SPI transmitter interrupt enable bit (SPTIE) enables the SPTE flag to generate
transmitter CPU interrupt requests, provided that the SPI is enabled (SPE = 1).
The SPI receiver interrupt enable bit (SPRIE) enables the SPRF bit to generate
receiver CPU interrupt requests, provided that the SPI is enabled (SPE = 1). (See
Figure 15-11.)
SPTE
SPTIE
SPE
SPI TRANSMITTER
CPU INTERRUPT REQUEST
SPRIE
SPRF
SPI RECEIVER/ERROR
CPU INTERRUPT REQUEST
ERRIE
MODF
OVRF
Figure 15-11. 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.
Data Sheet
222
MC68HC908MR32 • MC68HC908MR16 — Rev. 6.0
Serial Peripheral Interface Module (SPI)
MOTOROLA