service routine (ISR) should check the flag bits to determine which event caused the
interrupt. The service routine should also clear the flag bit(s) before returning from the
ISR (usually near the beginning of the ISR).
37.4.11.1 MODF
MODF occurs when the master detects an error on the SS pin. The master SPI must be
configured for the MODF feature (see the description of the C1[SSOE] bit). Once MODF
is set, the current transfer is aborted and the master (MSTR) bit in the SPIx_C1 register
resets to 0.
The MODF interrupt is reflected in the status register's MODF flag. Clearing the flag also
clears the interrupt. This interrupt stays active while the MODF flag is set. MODF has an
automatic clearing process that is described in the SPI Status Register.
37.4.11.2 SPRF
SPRF occurs when new data has been received and copied to the SPI receive data buffer.
After SPRF is set, it does not clear until it is serviced. SPRF has an automatic clearing
process that is described in the SPI Status Register details. If the SPRF is not serviced
before the end of the next transfer (that is, SPRF remains active throughout another
transfer), the subsequent transfers are ignored and no new data is copied into the Data
register.
37.4.11.3 SPTEF
SPTEF occurs when the SPI transmit buffer is ready to accept new data.
After SPTEF is set, it does not clear until it is serviced. SPTEF has an automatic clearing
process that is described in the SPI Status Register details.
37.4.11.4 SPMF
SPMF occurs when the data in the receive data buffer is equal to the data in the SPI
match register.
Functional Description
KL25 Sub-Family Reference Manual, Rev. 3, September 2012
682 Freescale Semiconductor, Inc.
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