Deserial Serial Peripheral Interface (DSPI)
MPC5510 Microcontroller Family Reference Manual, Rev. 1
Freescale Semiconductor
23-29
Preliminary
23.4
Functional Description
The DSPI supports full-duplex, synchronous serial communications between the MCU and peripheral
devices. The DSPI can also be used to reduce the number of pins required for I/O by serializing and
deserializing up to 16 parallel input/output signals from the eMIOS. All communications are through an
SPI-like protocol.
The DSPI has three configurations:
•
SPI configuration in which the DSPI operates as a basic SPI or a queued SPI.
•
DSI configuration in which the DSPI serializes and deserializes parallel input/output signals or bits
from memory mapped registers.
•
CSI configuration in which the DSPI combines the functionality of the SPI and DSI configurations.
The DCONF field in the DSPI
x
_MCR register determines the DSPI configuration. See
DSPI configuration values.
The DSPI
x
_CTAR0–DSPI
x
_CTAR7 registers hold clock and transfer attributes. The manner in which a
CTAR is selected depends on the DSPI configuration (SPI, DSI, or CSI). 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 DSI
configuration statically selects which CTAR to use. In CSI configuration, priority logic determines if SPI
data or DSI data is transferred. The type of data transferred (whether DSI or SPI) dictates which CTAR the
CSI configuration will use. See
Section 23.3.2.3, “DSPI Clock and Transfer Attributes Registers 0–7
,” for information on DSPI
x
_CTAR fields.
Offset: DSP 0x00CC
Access: Read
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
DESER_DATA
W
Reset
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Figure 23-15. DSPI Deserialization Data Register (DSPI_DDR)
Table 23-15. DSPI_DDR Field Description
Field
Description
bits 0–15
Reserved.
DESER_DATA Deserialized Data. Holds deserialized data that is presented as signal states to the parallel output signals.