Panasonic KX-T7453 Service Manual page 19

Layer 1 is the transmission method of Ping-Pong type which is AMI encoded. "SYNC/MAM/C/D/B1/B2/
P" data is received in the first half at 125us/frame. After 1 bit time has passed since receiving P data,
"SYNC/MAM/C/D/B1/B2/P" is transmitted. 1 bit time is 512kHz. 7-bit time idle term comes after
receiving P data.
6) PCM interface (between IC1 and IC2)
PCM interface consists of following 4 terminals.
The first PCM data is output from TXD at the positive edge of -FSYNC. The second data and the
followings are output at the positive edge of BCLK. After all data of 8 bit are output, the last data is
kept until the positive edge of next -FSYNC. The positive edge of BCLK should be within ±100ns from
the positive edge of -FSYNC.
The PCM data input from RXD is sampled at the negative edge of BCLK inside LSI. The sampling of
the first data is performed between the positive edge of -FSYNC and the first negative edge of BCLK.
After completing the sampling of all data of 8 bit, this sampling pauses until the next positive edge of -
FSYNC.
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