Datasheet

Serial Peripheral Interface (S08SPI16V1)
MC9S08JM60 Series Data Sheet, Rev. 3
Freescale Semiconductor 245
Figure 15-2. SPI Module Quick Start
MSTR CPOL CPHA SSOE LSBFE
MODFEN BIDIROE
SPIMODE
SPISWAI SPC0SPMIE
Additional configuration options.
SPPR0 SPR2 SPR1 SPR0SPPR2 SPPR1
Baud rate = (BUSCLK/SPPR[2:0])/SPR2[2:0]
Bit 15
Bit 7
Module Initialization (Slave):
Write: SPIxC1 to configure interrupts, set primary SPI options, slave mode select, and
system enable.
Write: SPIxC2 to configure optional SPI features, hardware match interrupt enable,
and 8- or 16-bit data transmission length
Write: SPIxMH:SPIxML to set hardware compare value that triggers SPMF (optional)
when value in receive data buffer equals this value.
Module Initialization (Master):
Write: SPIxC1 to configure interrupts, set primary SPI options, master mode select,
and system enable.
Write: SPIxC2 to configure optional SPI features, hardware match interrupt enable,
and 8- or 16-bit data transmission length
Write: SPIxBR to set baud rate
Write:
SPIxMH:SPIxML
to set
hardware compare value that triggers SPMF (optional)
when value in receive data buffer equals this value.
Module Use:
After SPI master initiates transfer by checking that SPTEF = 1 and then writing data to SPIDH/L:
Wait for SPRF, then read from SPIDH/L
Wait for SPTEF, then write to SPIDH/L
Data transmissions can be 8- or 16-bits long, and mode fault detection can be enabled for master mode in cases where
more than one SPI device might become a master at the same time. Also, some applications may utilize the receive data
buffer hardware match feature to trigger specific actions, such as when command data can be sent through the SPI or to
indicate the end of an SPI transmission.
SPIxC1
SPIxC2
SPIxBR
SPIxDH
SPIxDL
SPIE SPE SPTIE
Module/interrupt enables and configuration
Bit 14
Bit 13 Bit 12 Bit 11
Bit 10 Bit 9 Bit 8
Bit 6 Bit 5
Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
SPIxMH
Hardware Match Value
Bit 15
Bit 7
Bit 14
Bit 13 Bit 12 Bit 11
Bit 10 Bit 9 Bit 8
Bit 6 Bit 5
Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
MODFSPTEF
SPIxS
SPRF
SPMF
SPIxML