M68HC16 Z SERIES
QUEUED SERIAL MODULE
USER’S MANUAL
9-5
9.3 Queued Serial Peripheral Interface
The queued serial peripheral interface (QSPI) is used to communicate with external
devices through a synchronous serial bus. The QSPI is fully compatible with SPI sys-
tems found on other
Freescale
products, but has enhanced capabilities. The QSPI can
perform full duplex three-wire or half duplex two-wire transfers. A variety of transfer
rates, clocking, and interrupt-driven communication options is available.
displays a block diagram of the QSPI.
Figure 9-2 QSPI Block Diagram
QSPI BLOCK
CONTROL
REGISTERS
END QUEUE
POINTER
QUEUE
POINTER
STATUS
REGISTER
DELAY
COUNTER
COMPARATOR
PROGRAMMABLE
LOGIC ARRAY
80-BYTE
QSPI RAM
CHIP SELECT
COMMAND
DONE
4
4
2
BAUD RATE
GENERATOR
PCS[2:1]
PCS0/SS
MISO
MOSI
SCK
M
S
M
S
8/16-BIT SHIFT REGISTER
Rx/Tx DATA REGISTER
MSB
LSB
4
4
QUEUE CONTROL
BLOCK
CONTROL
LOGIC
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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