Chapter 20 Deserial Serial Peripheral Interface (DSPI)
MPC5602P Microcontroller Reference Manual, Rev. 4
460
Freescale Semiconductor
20.8
Functional description
The DSPI supports full-duplex, synchronous serial communications between the MCU and peripheral
devices. All communications are through an SPI-like protocol.
The DSPI supports only the serial peripheral interface (SPI) configuration in which the DSPI operates as
a basic SPI or a queued SPI.
The DCONF field in the DSPI
x
_MCR register determines the DSPI configuration. Refer to
the DSPI configuration values.
The DSPI
x
_CTAR0–DSPI
x
_CTAR7 registers hold clock and transfer attributes.The SPI configuration can
select which CTAR to use on a frame by frame basis by setting the CTAS field in the DSPI
x
_PUSHR.
The 16-bit shift register in the master and the 16-bit shift register in the slave are linked by the SOUT_
x
and SIN_
x
signals to form a distributed 32-bit register. When a data transfer operation is performed, data
is serially shifted a pre-determined number of bit positions. Because the registers are linked, data is
exchanged between the master and the slave; the data that was in the master’s shift register is now in the
shift register of the slave, and vice versa. At the end of a transfer, the TCF bit in the DSPI
x
_SR is set to
indicate a completed transfer.
illustrates how master and slave data is exchanged.
Address: Base + 0x007C (DSPI
x
_RXFR0)
Base + 0x0080 (DSPI
x
_RXFR1)
Base + 0x0084 (DSPI
x
_RXFR2)
Base + 0x0088 (DSPI
x
_RXFR3)
Base + 0x008C (DSPI
x
_RXFR4)
Access: User read-only
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
R
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
W
Reset
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
R
RXDATA
W
Reset
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Figure 20-11. DSPI Receive FIFO Registers 0–4 (DSPIx_RXFRn)
Table 20-17. DSPI
x
_RXFR
n
field description
Field
Description
0–15
Reserved, must be cleared.
16–31
RXDATA
[15:0]
Receive data
Contains the received SPI data.