mc68hc08ln56 Freescale Semiconductor, Inc, mc68hc08ln56 Datasheet - Page 115

• Manufacturer Part Number: mc68hc08ln56
• Description: M68hc08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

The SPI module allows full-duplex, synchronous, serial communication between the MCU and peripheral
devices, including other MCUs. Software can poll the SPI status flags or SPI operation can be
interrupt-driven. All SPI interrupts can be serviced by the CPU, and the transmitter empty (SPTE) and
receiver full (SPRF) flags can also be configured for DMA service.
During DMA transmissions, the DMA fetches data from memory for the SPI to transmit and/or the DMA
stores received data in memory.
The following paragraphs describe the operation of the SPI module.
Freescale Semiconductor
SPMSTR
RECEIVER/ERROR CPU INTERRUPT REQUEST
DIVIDER
CLOCK
TRANSMITTER CPU INTERRUPT REQUEST
CGMOUT ÷ 2
(FROM SIM)
TRANSMITTER DMA SERVICE REQUEST
RECEIVER DMA SERVICE REQUEST
÷ 128
SPE
÷ 32
÷ 2
÷ 8
MC68HC08LN56 • MC68HC708LN56 General Release Specification, Rev. 2.1
SPR1
SELECT
CLOCK
SPR0
Figure 11-2. SPI Module Block Diagram
7
CONTROL
TRANSMIT DATA REGISTER
RECEIVE DATA REGISTER
6
SPI
SHIFT REGISTER
INTERNAL BUS
5
4
3
MODF
OVRF
SPRF
SPTE
SPMSTR
2
1
MODFEN
ERRIE
SPTIE
SPRIE
DMAS
SPE
0
CLOCK
LOGIC
CPHA
CPOL
SPWOM
M
S
CONTROL
LOGIC
PIN
Functional Description
MISO
MOSI
SPSCK
SS
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