Motorola XTS 2500 Service Manual page 325

VHF Troubleshooting Waveforms: RX Serial Audio Port (SAP)
7.1.38RX Serial Audio Port (SAP)
Note: TX is identical, except the data is probed at test point "TX".
Trace 1: 8 kHz frame sync (each word is 13 bits after falling edge of FSYNC)
Trace 2: SAP data at R626 (audio data from MAKO CODEC to Patriot DSP)
Note: Transmit is identical, except data acquired at R625
Trace 3: 512kHz bit clock at R616. (Codec_DCLK).
6816985H01-F
7.1-39
February 14, 2012