MPC5200B Users Guide, Rev. 1
15-12 Freescale Semiconductor
PSC Registers—MBAR + 0x2000, 0x2200, 0x2400, 0x2600, 0x2800, 0x2C00
15.2.4 Clock Select Register (0x04) CSR
The MPC5200B supports only the internal clock as source for the UART / SIR clock generation. For the UART clock generation a prescaler
by 32 or 4 is available. For the SIR clock generation only the prescaler by 32 is valid. After reset, the prescaler by 4 for the UART mode and
the prescaler by 32 for the SIR mode is selected. Writing “1110” to this register will stop the UART / SIR clock generation.
15.2.5 Command Register (0x08)CR
The write-only command registers (CR), provide the commands to the PSC in all modes. Only multiple commands that do not conflict can be
specified in a single write to a CR. For example, reset Tx and enable Tx cannot be specified in one command.

Table15-14. Clock Select Register (0x04) for UART / SIR Mode

msb 012345678 9 101112131415 lsb
R
WRCS TCS Reserved
RESET:000000000 0 0 000 0 0

Table15-15. Clock Select Register (0x04) for other Modes

msb 012345678 9 101112131415 lsb
RReserved
W
RESET:000000000 0 0 000 0 0
Bit Name Description
0:3 RCS UART—Receiver Clock Select Register
0000 -1101 = choose the prescaler by 32 for the UART receive clock generation
1110 = disable the clock generation
1111 = choose the prescaler by 4 for the UART receive clock generation
SIR —Clock Select Register
1110 = disable the clock generation
others = choose the prescaler by 32 for the SIR receive clock generation
other Modes—Reserved
4:7 TCS UART—Transmitter Clock Select Register
0000 -1101 = choose the prescaler by 32 for the UART transmit clock generation
1110 = disable the clock generation
1111 = choose the prescaler by 4 for the UART transmit clock generation
SIR —Clock Select Register
1110 = disable the clock generation
others = choose the prescaler by 32 for the SIR transmit clock generation
other Modes—Reserved
8:15 — Reserved