Functional Description
MCF548x Reference Manual, Rev. 3
Freescale Semiconductor 26-39

Figure 26-31. Waveform of Modem16 Mode

The function of this mode is the same as 8-bit modem mode except that the transmit/receive data length is

16 bit.

26.4.5 AC97 Mode

Figure 26-32 shows the waveform in AC97 modem mode.

Figure 26-32. Waveform of AC97 Mode

In AC97 mode, the PSCBCLK is the bit clock input and, different from 8/16 bit modem mode, the

PSCnRTS is the frame sync output. Figure 26-33 shows an example connection to a AC97 CODEC chip.

Figure 26-33. An Example Connection to AC97 CODEC

PSCBCLK
D15 D12 D11D14 D13 D10 D9
PSCFSYNC
PSCnTXD
PSCnRXD
D4 D3D6 D5 D2 D1 D0D8 D7
D15 D12 D11D14 D13 D10 D9 D4 D3D6 D5 D2 D1 D0D8 D7
PSCBCLK
D15 D1 D0D14 D19 D18
PSCnRTS
PSCnTXD
PSCnRXD
D19 D18D0 D1D1
D15 D1 D0D14 D19 D18 D19 D18D0 D1D1
81.4 ns (12.288 MHz)
20.8 µs (48.0 kHz)
D0
D0
D15
D15
D14
D14
Slot #0 (16-bit) Slot #1 (20-bit) Slot #12 (20-bit)
BITCLK
SYNC
XTL_IN
XTL_OUT
SDATA_IN
RESET
SDATA_OUT
AC97 CODEC
PSC_BIT_CLK
PSC_RTS
PSC_RXD
PSC_TXD
PSC