Memory Map/Register Definition
MCF548x Reference Manual, Rev. 3
Freescale Semiconductor 26-11

The upper 4 bits set the receiver and the lower 4 bits set the transmitter clock source. To use the system

bus clock for both the transmitter and receiver, program the PSCCSR with 0xDD. It is possible to program

the transmitter and the receiver with different clock sources.

26.3.3.5 Command Register (PSCCRn)

The PSCCR is used to supply commands to the PSC. Multiple commands can be specified in a single write

to the PSCCR if the commands are not conflicting. For example, reset transmitter and enable transmitter

commands cannot be specified in a single command.

76543210
R
WRCSEL TCSEL
Reset11011101
Reg
Addr
MBAR + 0x8604 (PSC0); 0x8704 (PSC1); 0x8804 (PSC2); 0x8904 (PSC3)

Figure 26-6. Clock Select Register (PSCCSRn)

Figure 26-7. PSCCSRn Field Descriptions

Bits Name Description
7–4 RCSEL In UART or SIR mode, this is the receiver clock select. Table 26-6 shows the bit settings for this field.
In all other modes, this field is reserved.
3–0 TCSEL In UART or SIR mode, this is the transmitter clock select. Table 26-6 shows the bit settings for this field.
In all other modes, this field is reserved.

Table 26-6. RCSEL[3:0] and TCSEL[3:0]

RCSEL[3:0] or
TCSEL[3:0] UART Mode SIR Mode
0000 – 1101 System Bus
Clock
System Bus
Clock
1110 × 16 CTM clock
× 16 CTM clock
1111 × 1 CTM clock
76543210
R0
WMISC TXC RXC
Reset00000000
Reg
Addr
MBAR + 0x8608 (PSC0); 0x8708 (PSC1); 0x8808(PSC2); 0x8908 (PSC3)

Figure 26-8. PSC Command Register (PSCCRn)