Rainbow Electronics DS2132A_Q - Manual (Page 4)

DS2132A/Q
041295 4/17
DS2132A BLOCK DIAGRAM Figure 2
Playback
Gain Control
Record
Gain Control
DTMF/Level/
FAX Tone
Detection
Speech
Compression
Command
Processor
Speech
Expansion
DTMF/Musical
Tone
Generation
PCMOUT
PCMIN
CDOUT
CDIN
Loopback
T
o
CODEC
“PCM” Side
T
o
Microcontroller
“Compressed Data” Side
Threshold
OPERATION OF THE CD AND PCM PORTS
As mentioned earlier, the DS2132A essentially contains
two separate serial ports, one for the DS2132A to micro-
controller interface (the CD Port ) and one for the CO-
DEC to DS2132A interface (the PCM Port). The Com-
pressed Data (CD) Port is used to send compressed
speech information from the DS2132A to the microcon-
troller and vice versa. The CD Port is also used to moni-
tor the current status of the DS2132A and it is used to
issue instructions to the DS2132A. The CD Port con-
sists of the CDIN, CDOUT, CLK, and FS pins (the CLK
and FS pins are shared with the CODEC). The PCM
Port is used to transfer uncompressed speech data be-
tween the DS2132A and the CODEC. It consists of the
PCMIN, PCMOUT, CLK, and FS pins. Figure 3 details
the DS2132A CD and PCM port signals. All commu-
nication begins with the frame sync (FS) signal. It indi-
cates to the DS2132A and the CODEC that a byte of in-
formation will follow. Note that the PCM Port operates
on a MSB first basis and the CD Port operates on a LSB
first basis.