Chapter 20 Deserial Serial Peripheral Interface (DSPI)
MPC5602P Microcontroller Reference Manual, Rev. 4
438
Freescale Semiconductor
20.3
Overview
The register content is transmitted using an SPI protocol. There are three DSPI modules (DSPI_0, DSPI_1,
and DSPI_2) on the device. The modules are identical except that DSPI_0 has four additional chip select
(CS) lines.
For queued operations, the SPI queues reside in internal SRAM that is external to the DSPI. Data transfers
between the queues and the DSPI FIFOs are accomplished through the use of the eDMA controller or
through host software.
shows a DSPI with external queues in internal SRAM.
Figure 20-2. DSPI with queues and eDMA
20.4
Features
The DSPI supports these SPI features:
•
Full-duplex, three-wire synchronous transfers
•
Master and slave modes
•
Buffered transmit and receive operation using the TX and RX FIFOs, with depths of 5 entries
•
Visibility into TX and RX FIFOs for ease of debugging
•
FIFO bypass mode for low-latency updates to SPI queues
•
Programmable transfer attributes on a per-frame basis
— 8 clock and transfer attribute registers
— Serial clock with programmable polarity and phase
— Programmable delays
– CS to SCK delay
– SCK to CS delay
– Delay between frames
— Programmable serial frame size of 4 to 16 bits, expandable with software control
Internal SRAM
TX queue
RX queue
Address/control
TX FIFO
DSPI
RX FIFO
RX data
TX data
TX data
RX data
Shift register
eDMA controller
Address/control
or host CPU