Freescale Semiconductor MPC5553 - Page 899

MPC5553/MPC5554 Microcontroller Reference Manual, Rev. 5
20-26 Freescale Semiconductor
20.3.2.8 DSPI Transmit FIFO Registers 0–3 (DSPIx_TXFRn)
The DSPIx_TXFRn 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 DSPIx_TXFRn
registers does not alter the state of the TX FIFO. The MPC5553/MPC5554 uses four registers to
implement the TX FIFO, that is DSPIx_TXFR0–DSPIx_TXFR3 are used.
20.3.2.9 DSPI Receive FIFO Registers 0–3 (DSPIx_RXFRn)
The DSPIx_RXFRn registers provide visibility into the RX FIFO for debugging purposes. Each register is
an entry in the RX FIFO. The DSPIx_RXFR registers are read-only. Reading the DSPIx_RXFRn registers
does not alter the state of the RX FIFO. The MPC5553/MPC5554 uses four registers to implement the RX
FIFO, that is DSPIx_RXFR0–DSPIx_RXFR3 are used.
01 23456789101112131415
RTXCMD
W
Reset00 00000000000000
Reg Addr Base + 0x003C (DSPIx_TXFR0); 0x0040 (DSPIx_TXFR1); 0x0044 (DSPIx_TXFR2); 0x0048 (DSPIx_TXFR3)
16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
RTXDATA
W
Reset00 00000000000000
Reg Addr Base + 0x003C (DSPIx_TXFR0); 0x0040 (DSPIx_TXFR1); 0x0044 (DSPIx_TXFR2); 0x0048 (DSPIx_TXFR3)
Figure 20-10. DSPI Transmit FIFO Register 0–3 (DSPIx_TXFRn)
Table 20-10. DSPIx_TXFRn Field Descriptions
Bits Name Description
0–15 TXCMD
[0:15]
Transmit command. Contains the command that sets the transfer attributes for the SPI
data. See Section 20.3.2.6, “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.