Deserial Serial Peripheral Interface (DSPI)
25-2
Freescale Semiconductor
PXR40 Microcontroller Reference Manual, Rev. 1
25.1.1
Overview
The Deserial Serial Peripheral Interface (DSPI) block provides a synchronous serial bus for
communication between an MCU and an external peripheral device. The DSPI supports pin count
reduction through serialization and deserialization of parallel signals transmitted over the SPI serial link.
The DSPI has three configurations:
•
Serial Peripheral interface (SPI) Configuration where the DSPI operates as a basic SPI or as a
queued SPI through the use of internal FIFOs.
•
Deserial serial interface (DSI) configuration where the DSPI serializes eTPU and eMIOS output
channels and deserializes the received data by placing the data on the eTPU and eMIOS input
channels and as inputs to the external interrupt request submodule of the SIU.
•
Combined Serial Interface (CSI) Configuration where the DSPI operates in both SPI and DSI
configurations interleaving DSI frames with SPI frames, giving priority to SPI frames.
For queued operations the SPI queues reside in system RAM which is external to the DSPI. Data transfers
between the queues and the DSPI FIFOs are accomplished through the use of a DMA controller or through
host software.
shows a DSPI with external queues in system RAM.
Figure 25-2. DSPI with Queues and DMA
25.1.2
Features
The DSPI supports these SPI features:
•
Full-duplex, three-wire synchronous transfers
•
Master and Slave Mode
•
Buffered transmit operation using the TX FIFO (depth of 4 entries)
•
Buffered receive operation using the RX FIFO (depth of 4 entries)
•
TX and RX FIFOs can be disabled individually for low-latency updates to SPI queues
•
Visibility into TX and RX FIFOs for ease of debugging
System RAM
DSPI
DMA Controller
TX Queue
RX FIFO
TX FIFO
Shift Register
Data
Data
Addr/Ctrl
RX Queue
Data
Data
Addr/Ctrl
Done
Req
Summary of Contents for PXR4030
Page 1: ...PXR40 Microcontroller Reference Manual Devices Supported PXR4030 PXR4040 PXR40RM Rev 1 06 2011...
Page 30: ...PXR40 Microcontroller Reference Manual Rev 1 Freescale Semiconductor xxx...
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Page 66: ...Memory Map PXR40 Microcontroller Reference Manual Rev 1 2 4 Freescale Semiconductor...
Page 120: ...Signal Descriptions 3 54 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...
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