mc68hc908gr8a Freescale Semiconductor, Inc, mc68hc908gr8a Datasheet - Page 175

• Manufacturer Part Number: mc68hc908gr8a
• Description: M68hc08 Microcontrollers Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

Chapter 15
Serial Peripheral Interface (SPI) Module
15.1 Introduction
This section describes the serial peripheral interface (SPI) module, which allows full-duplex,
synchronous, serial communications with peripheral devices.
The text that follows describes the SPI. The SPI I/O pin names are SS (slave select), SPSCK (SPI serial
clock), MOSI (master out slave in), and MISO (master in/slave out). The SPI shares four I/O pins with four
parallel I/O ports.
15.2 Features
Features of the SPI module include:
15.3 Functional Description
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.
If a port bit is configured for input, then an internal pullup device may be enabled for that port bit.
The following paragraphs describe the operation of the SPI module. Refer to
of the SPI I/O registers.
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Full-duplex operation
Master and slave modes
Double-buffered operation with separate transmit and receive registers
Four master mode frequencies (maximum = bus frequency ÷ 2)
Maximum slave mode frequency = bus frequency
Serial clock with programmable polarity and phase
Two separately enabled interrupts:
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Mode fault error flag with CPU interrupt capability
Overflow error flag with CPU interrupt capability
Programmable wired-OR mode
I/O (input/output) port bit(s) software configurable with pullup device(s) if configured as input port
bit(s)
SPRF (SPI receiver full)
SPTE (SPI transmitter empty)
MC68HC908GR8A • MC68HC908GR4A Data Sheet, Rev. 5
Figure 15-3
for a summary
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