Rainbow Electronics DS2132A_Q User Manual
Page 5
DS2132A/Q
041295 5/17
CD & PCM PORT I/O DIAGRAM Figure 3
CLK
1
FS
2
PCMIN
PCMOUT
CDIN
CDOUT
MSB
LSB
MSB
LSB
LSB
MSB
LSB
MSB
3-STATE
3-STATE
NOTES:
1. The CLK period must be between 128 KHz and 4.096 MHz
2. The FS pulse must be between 1 and 9 (inclusive) CLK periods long
On the PCM Port, data will be transferred from the CO-
DEC to the DS2132A via one path and transferred from
the DS2132A to the CODEC via another path. These
transfers take place every 125
µ
s (as determined by the
FS signal). Although the CD Port also transfers data ev-
ery 125
µ
s, it operates much differently than does the
PCM Port. The CD Port constantly toggles back and
forth in its data transfer direction. During one frame
sync, the microcontroller will transfer either com-
pressed speech data or command information to the
DS2132A and during the next frame sync, the transfer
direction will switch and the DS2132A will send either
compressed speech data or status information to the
microcontroller. Hence, the CD Port is truly bidirection-
al. See Figure 4.