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

SPI transmitter CPU interrupt request (SPTIE = 1, SPE = 1)

 

 

SPRF receiver full

SPI receiver CPU interrupt request (SPRIE = 1)

 

 

OVRF overflow

SPI receiver/error interrupt request (ERRIE = 1)

 

 

MODF mode fault

SPI receiver/error interrupt request (ERRIE = 1)

 

 

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.

These sources in the SPI status and control register can generate 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 set, SPTE can generate either an SPTE or CPU interrupt request.

MC68HC908MR32 • MC68HC908MR16 Data Sheet, Rev. 6.1

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Freescale Semiconductor

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Freescale Semiconductor MC68HC908MR32, MC68HC908MR16 manual SPI Interrupts, Flag Request
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MC68HC908MR16, MC68HC908MR32 specifications

Freescale Semiconductor's MC68HC908MR32 and MC68HC908MR16 microcontrollers are part of the popular HC08 family, designed primarily for embedded applications. These microcontrollers are particularly favored in automotive, industrial, and consumer product sectors due to their reliability and versatility.

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