Owner manual

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
To CODEC
“PCM” Side
To 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.