mc9s12xs128 Freescale Semiconductor, Inc, mc9s12xs128 Datasheet - Page 447

• Manufacturer Part Number: mc9s12xs128
• Description: Hcs12 Microcontrollers 16-bit Automotive Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

15.4
The SPI module allows a duplex, synchronous, serial communication between the MCU and peripheral
devices. Software can poll the SPI status flags or SPI operation can be interrupt driven.
The SPI system is enabled by setting the SPI enable (SPE) bit in SPI control register 1. While SPE is set,
the four associated SPI port pins are dedicated to the SPI function as:
Freescale Semiconductor
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Receive Shift Register
Receive Shift Register
Slave select (SS)
Serial clock (SCK)
Master out/slave in (MOSI)
Master in/slave out (MISO)
SPI Data Register
SPI Data Register
Functional Description
SPIF
SPIF
Data A Received
Data A Received
Figure 15-10. Reception with SPIF serviced too late
Figure 15-9. Reception with SPIF serviced in Time
= Unspecified
= Unspecified
S12XS Family Reference Manual, Rev. 1.10
Data A
Data A
Data A
Data A
= Reception in progress
= Reception in progress
Data B Received
Data B Received
Data B
Data B
SPIF Serviced
Data B Lost
SPIF Serviced
Data B
Serial Peripheral Interface (S12SPIV5)
Data C Received
Data C Received
Data C
Data C
Data C
Data C
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