Software Environment
MCF548x Reference Manual, Rev. 3
Freescale Semiconductor 26-53

26.7.2.6 MIR Mode

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

MIR mode. Here is a sample sequence when the input frequency of PSCBCLK is 18.432 MHz. (1.152

MHz x 16).

8 PSCMR2 07 CM[1:0]=00 Normal mode (not test mode)
TxRTS=0 PSCnRTS is not controlled by transmitter
TxCTS=0 PSCnCTS does not control transmitter
SB[3:0]=0111 1 stop bit
9 PSCIRCR1 00 FD=0 Receiver is disabled while transmitting
SPUL=1 Pulse width is 1.6 us
10 PSCIRSTR 36 IRSTIM=54 (dec) Counter value for 1.6 us pulse
11 PSCRFCR 0F WRITE TAG = 00 Not EOF
FRMEN=1 Enable frame mode
GR[2:0]=100 Granularity is 4 byte
12 PSCTFCR 0F WRITE TAG = 00 Not EOF
FRMEN=1 Enable frame mode
GR[2:0]=100 Granularity is 16 byte
13 PSCRFAR 00F0 ALARM[8:0]=0F0 Request is asserted if # of data >= 240
14 PSCTFAR 00F0 ALARM[8:0]=0F0 Request is asserted if # of empty >= 240
15 PSCCR 04 TC=01 Enable transmitter
RC=00 Receiver remains at disabled state.

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

Step
No. Register Value Details Meaning
1 PSCSICR 05 SIM[2:0]=101 MIR mode
2 PSCIRMFD 0F FREQL=0 1.152 Mbps mode
M_FDIV[4:0]=01111 Frequency divide ratio is 16.
So f(PSCBCLK) should be 18.432 MHz.
3 PSCCR 20 MISC=010 Reset receiver and RxFIFO
30 MISC=011 Reset transmitter and TxFIFO
40 MISC=100 Reset all error status
10 MISC=001 Reset MR pointer

Table 26-44. A Sample Initialization Sequence for SIR Mode (Continued)

Step
No. Register Value Details Meaning