MCF548x Reference Manual, Rev. 3
26-2 Freescale Semiconductor
Backward compatible with the MC68681
5,6,7,8 bits data plus parity
Odd, even, none, or force parity
Stop bit width programmable in 1/16 bit increments
Parity, framing, and overrun error detection
Automatic PSCnCTS and PSCnRTS modem control signals
IrDA 1.0 SIR mode (SIR)
Baud rate range: 2400 to 115200 bps
Selectable pulse width: either 3/16 bit duration or 1.6 us.
IrDA 1.1 MIR mode (MIR)
Baud rate: 0.576 Mbps or 1.152 Mbps.
IrDA 1.1 FIR mode (FIR)
Baud rate: 4.0 Mbps
8-bit soft modem mode (modem8)
16-bit soft modem mode (modem16)
AC97 soft modem mode (AC97)
The three soft modem modes (modem8, modem16, and AC97) are jointly referred to as “modem mode.”
The three IR modes (SIR, MIR, and FIR) are jointly referred to as “IrDA mode.”

26.2 Signal Description

26.2.1 PSCnCTS/PSCBCLK

These signals either operate as the clear to send input signals in UART mode or the bit clock input signals
in modem modes and IrDA modes. Please refer to ,” for information about how to program this signal
function.
In MIR and FIR mode, the frequency is a multiple of the input bit clock frequency, and the bit clock
frequency should be within +/-0.1% and +/-0.01% of the ideal one, respectively.

26.2.2 PSCnRTS/PSCFSYNC

These signals act as transmitter request to send output in UART mode, the frame sync input in modem8
and modem16 modes, or the RTS output (which acts as frame sync) in AC97 modem mode.
Refer to the Chapter 15, “GPIO,” and Section 26.3.3.5, “Command Register (PSCCRn),” for information
about how to program this signal function.

26.2.3 PSCnRXD

PSCnRXD are the receiver serial data inputs for the PSC modules. When the PSC clock is stopped for
power-down mode, any transition on the signals restarts them.