MCF548x Reference Manual, Rev. 3
26-54 Freescale Semiconductor

26.7.2.7 FIR Mode

Applying the clock to the PSCBCLK input and programming the control registers are required to initialize

in FIR mode. Here is a sample sequence when the input frequency of PSCBCLK is 64 MHz. Steps 3 to 11

are the same as in MIR mode.

4 PSCMR1 73 RxIRQ=1 receiver interrupt is from FU (over threshold)
5 PSCIMR 0380 IPC=0 Disable input port change interrupt
RxRDY or FU=1 Enable receiver interrupt/request
TxRDY=1 Enable transmitter interrupt/request
DEOF=1 Enable DEOF interrupt/request
6 PSCIRCR1 02 FD=0 Receiver is disabled while transmitting
SIPEN=1 Send SIP after every frame
7 PSCIRCR2 00 SIPREQ=0 SIP is not requested to send now
ABORT=0 Not send abort sequence now
NXTEOF=0 Next write is not EOF
8 PSCRFCR 0F WRITE TAG = 00 Not EOF
FRMEN=1 Enable frame mode
GR[2:0]=100 Granularity is 4 byte
9 PSCTFCR 0F WRITE TAG = 00 Not EOF
FRMEN=1 Enable frame mode
GR[2:0]=100 Granularity is 16 byte
10 PSCRFAR 00F0 ALARM[8:0]=0F0 Request is asserted if # of data >= 240
11 PSCTFAR 00F0 ALARM[8:0]=0F0 Request is asserted if # of empty >= 240
12 PSCCR 04 TC=01 Enable transmitter
RC=00 receiver remains at disabled state.

Table 26-46. A Sample Initialization Sequence for FIR Mode

Step
No. Register Value Details Meaning
1 PSCSICR 06 SIM[2:0]=110 FIR mode
2 PSCIRFFD 0F F_FDIV[3:0]=0111 Frequency divide ratio is 8.
So f(PSCBCLK) should be 64 MHz.

Table 26-45. A Sample Initialization Sequence for MIR Mode (Continued)

Step
No. Register Value Details Meaning