
MOTOROLA
Queued Serial Peripheral Interface (QSPI) Module
16-1
Section 16
Queued Serial Peripheral Interface (QSPI) Module
This section describes the queued serial peripheral interface (QSPI) module. Following a feature-set
overview is a description of operation including details of the QSPI’s internal RAM organization. The
section concludes with the programming model and a timing diagram.
16.1
OVERVIEW
The queued serial peripheral interface module provides a serial peripheral interface with queued transfer
capability. It allows users to queue up to 16 transfers at once, eliminating CPU intervention between
transfers. Transfer RAMs in the QSPI are indirectly accessible using address and data registers. The QSPI
is functionally similar to the QSM in the 68332.
16.2
FEATURES
Programmable queue to support up to 16 transfers without user intervention
Supports transfer sizes of 8 to 16 bits in 1-bit increments
Four peripheral chip-select lines for control of up to 15 devices
Baud rates from 134 Kbps to 16.7 Mbps at a CPU clock of 140 MHz
Programmable delays before and after transfers
Programmable clock phase and polarity
Supports wraparound mode for continuous transfers
16.3
MODULE DESCRIPTION
The QSPI module communicates with the integrated ColdFire CPU using internal memory mapped
16.3.1
INTERFACE AND PINS
The module provides as many as 15 ports and a total of seven signals: QSPI_Dout, QSPI_Din,
QSPI_CLK, QSPI_CS [3:0].
Peripheral chip-select signals, QSPI_CS[3:0], are used to select an external device as the source or
destination for serial data transfer. Signals are asserted at a logic level corresponding to the value of the
QSPI_CS[3:0] bits in the command RAM whenever a command in the queue is executed. More than one
chip-select signal can be asserted simultaneously.
Although QSPI_CS[3:0] will function as simple chip selects in most applications, up to 15 ports can be
selected by decoding them with an external 4-to-16 decoder.
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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