
Deserial – Serial Peripheral Interface (DSPI)
PXN20 Microcontroller Reference Manual, Rev. 1
30-4
Freescale Semiconductor
30.1.3.1
SPI Configuration
The SPI configuration allows the DSPI to send and receive serial data. This configuration allows the DSPI
to operate as a basic SPI block with the FIFOs providing support for external queue operation. Data to be
transmitted and data received reside in separate FIFOs. The FIFOs can be popped and pushed by host
software or by a DMA controller.
30.1.3.2
DSI Configuration
In the DSI configuration, the DSPI serializes as many as 16 parallel input signals or register bits. The DSPI
also deserializes the received data to parallel output signals or to a memory-mapped register. The data is
transferred using a SPI-like protocol.
Specifically in the TSB configuration, detailed on
Section 30.4.10, Timed Serial Bus (TSB),
the DSPI
serializes from 4 to 32 Parallel Input signals or register bits. The TSB downstream frame used to
communicate with a single slave is shown in
.
30.1.3.3
CSI Configuration
The CSI configuration is a combination of the SPI and DSI configurations. In this configuration, the DSPI
interleaves DSI data with SPI data. Interleaving is done on the frame boundaries. In this configuration, SPI
data transmission has higher priority than DSI data transmission.
30.1.4
Modes of Operation
The DSPI has five modes of operation that can be divided into two categories; block-specific modes such
as master, slave, and module disable modes; and MCU-specific modes like external halt and debug modes.
The block-specific modes are entered by host software writing to a register. The MCU-specific modes are
controlled by signals external to the DSPI. The MCU-specific modes are modes that the entire MCU may
enter, in parallel to the DSPI being in one of its block-specific modes.
30.1.4.1
Master Mode
Master mode allows the DSPI to initiate and control serial communication. In this mode, the SCK signal
and the PCS[
x
] signals are controlled by the DSPI and configured as outputs.
30.1.4.2
Slave Mode
Slave mode allows the DSPI to communicate with SPI/DSI bus masters. In this mode the DSPI responds
to externally controlled serial transfers. The DSPI cannot control serial transfers in slave mode. In this
mode, the SCK signal and the PCS[0]/SS signal are configured as inputs and provided by a bus master.
30.1.4.3
Module Disable Mode
Module disable mode is used for MCU power management. The clock to the non-memory mapped logic
in the DSPI can be stopped while in the module disable mode. Logic external to the DSPI is needed to fully
implement the module disable mode.
Summary of Contents for PXN2020
Page 1: ...PXN20 Microcontroller Reference Manual Devices Supported PXN2020 PXN2120 PXN20RM Rev 1 06 2011...
Page 42: ...PXN20 Microcontroller Reference Manual Rev 1 lxiv Freescale Semiconductor...
Page 64: ...Introduction PXN20 Microcontroller Reference Manual Rev 1 1 22 Freescale Semiconductor...
Page 112: ...Signal Description PXN20 Microcontroller Reference Manual Rev 1 3 44 Freescale Semiconductor...
Page 118: ...Resets PXN20 Microcontroller Reference Manual Rev 1 4 6 Freescale Semiconductor...
Page 372: ...e200z6 Core Z6 PXN20 Microcontroller Reference Manual Rev 1 13 8 Freescale Semiconductor...
Page 412: ...e200z0 Core Z0 PXN20 Microcontroller Reference Manual Rev 1 14 14 Freescale Semiconductor...
Page 821: ...Media Local Bus MLB PXN20 Microcontroller Reference Manual Rev 1 Freescale Semiconductor 27 49...
Page 822: ...Media Local Bus MLB PXN20 Microcontroller Reference Manual Rev 1 27 50 Freescale Semiconductor...
Page 1376: ...Memory Map PXN20 Microcontroller Reference Manual Rev 1 A 118 Freescale Semiconductor...