Freescale Semiconductor MPC5200B - Manual (Page 553)

MPC5200B Users Guide, Rev. 1
15-42 Freescale Semiconductor
PSC Registers—MBAR + 0x2000, 0x2200, 0x2400, 0x2600, 0x2800, 0x2C00
15.2.40 Tx FIFO Control (0x88)—TFCNTL
15.2.41 Tx FIFO Alarm (0x8E)—TFALARM
15.2.42 Tx FIFO Read Pointer (0x92)—TFRPTR
14 ALARM The FIFO is requesting service from either BestComm or CPU. See Section 15.4, PSC FIFO
System for a detailed description.
15 EMPTY FIFO Empty. The FIFO is completely empty.
Table 15-67. Tx FIFO Control (0x88)
msb 0 1 2 3 4 5 6 7 lsb
R Reserved WFR COMP FRAME GR[2:0]
W
RESET: 0 0 0 0 1 0 0 1
Bit Name Description
0:1 — Reserved
2 WFR Write frame. Not applicable for PSC FIFOs, since the PSCs do not recognize frame formats in
the serial data stream.
3 COMP Re-enable requests on frame transmission completion. Not applicable to PSC FIFO’s, since
the PSCs do not recognize frame formats in the serial data stream.
4 FRAME Frame mode enable. THIS BIT MUST BE CLEARED BY WRITING A ‘0’ TO IT, since the PSCs
do not recognize frame formats in the serial data stream.
5:7 GR[2:0] Last transfer granularity. Four times this value is the amount of data remaining in the FIFO at
which the ALARM bit in the status register will go low/inactive. See
Section 15.4, PSC FIFO
System for details.
Table 15-68. Tx FIFO Alarm (0x8E)
msb 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 lsb
R Reserved ALARM
W
RESET: 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1
Bit Name Description
0:3 — Reserved
4:15 ALARM “Almost empty” threshold level. Amount of data remaining in the Tx FIFO at which the ALARM
bit in the status register goes high/active. See
Section 15.4, PSC FIFO System for details
Table 15-69. Tx FIFO Read Pointer (0x92)
msb 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 lsb
R Reserved R_PTR
W
RESET: 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Bit Name Description