Chapter 20 Deserial Serial Peripheral Interface (DSPI)
MPC5602P Microcontroller Reference Manual, Rev. 4
Freescale Semiconductor
459
20.7.2.8
DSPI Transmit FIFO Registers 0–4 (DSPI
x
_TXFR
n
)
The DSPI
x
_TXFR
n
registers provide visibility into the TX FIFO for debugging purposes. Each register is
an entry in the TX FIFO. The registers are read-only and cannot be modified. Reading the DSPI
x
_TXFR
n
registers does not alter the state of the TX FIFO. The MCU uses five registers to implement the TX FIFO,
that is DSPI
x
_TXFR0–DSPI
x
_TXFR4 are used.
20.7.2.9
DSPI Receive FIFO Registers 0–4 (DSPI
x
_RXFR
n
)
The DSPI
x
_RXFR
n
registers provide visibility into the RX FIFO for debugging purposes. Each register is
an entry in the RX FIFO. The DSPI
x
_RXFR registers are read-only. Reading the DSPI
x
_RXFR
n
registers
does not alter the state of the RX FIFO. The device uses five registers to implement the RX FIFO, that is
DSPI
x
_RXFR0–DSPI
x
_RXFR4 are used.
Table 20-15. DSPI
x
_POPR field descriptions
Field
Description
0–15
Reserved, must be cleared.
16–31
RXDATA
[0:15]
Received data
The RXDATA field contains the SPI data from the RX FIFO entry pointed to by the pop next
data pointer (POPNXTPTR).
Address: Base + 0x003C (DSPI
x
_TXFR0)
Base + 0x0040 (DSPI
x
_TXFR1)
Base + 0x0044 (DSPI
x
_TXFR2)
Base + 0x0048 (DSPI
x
_TXFR3)
Base + 0x004C (DSPI
x
_TXFR4)
Access: User read-only
0
1
2
4
5
6
7
8
9
10
11
12
13
14
15
R
TXCMD
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
TXDATA
W
Reset
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Figure 20-10. DSPI Transmit FIFO Register 0–4 (DSPI
x
_TXFR
n
)
Table 20-16. DSPI
x
_TXFR
n
field descriptions
Field
Description
0–15
TXCMD
[0:15]
Transmit command
Contains the command that sets the transfer attributes for the SPI data. Refer to
Section 20.7.2.6, “DSPI PUSH TX FIFO Register (DSPIx_PUSHR)
for details on the
command field.
16–31
TXDATA
[0:15]
Transmit data
Contains the SPI data to be shifted out.