W6691CD WINBOND [Winbond], W6691CD Datasheet - Page 20

• Manufacturer Part Number: W6691CD
• Description: ISDN S/T Interface Transceiver
• Manufacturer: WINBOND [Winbond]

The peripheral simple I/O is used to control other peripheral devices such as CODEC, SLIC, DTMF detector,
LEDs.
7.1.2 Interface and Operating Modes
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TE , LT-S and LT-T modes are configured by setting mode pins (M1 and M0).
7.2.1 S/T Interface Transmitter/Receiver
transmission on the S/T interface. The binary "1" is represented by no line signal (zero volt), whereas a binary
"0" is represented by a positive or negative pulse.
consists of 48 bits, which corresponds to a 192 kbit/s line rate. Each frame carries two octets of B1 channel,
two octets of B2 channel and four D channel bits. Therefore, the 2B+D data rate is 144 kbit/s. The frame
structure is shown in Fig.7.1.
following the framing bit balancing bit is of the same polarity as the framing bit balancing bit, and subsequent
binary zeros must alternate in polarity.
The W6691 can be configured for the following application:
According to ITU-T I.430, pseudo-ternary code with 100% pulse width is used in both directions of
Data transmissions on the S/T interface are arranged as frame structures. The frame is 250 s long and
The frame begin is marked by a framing bit, which is followed by a DC balancing bit. The first binary "0"
ISDN terminals
ISDN subscriber line termination --- LT-S mode (M1=1 & M0=0)
ISDN trunk line termination ---LT-T mode (M1=0 & M0=1)
--- TE mode (M1=0 & M0=0)
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Preliminary W6691
Publication Release Date: Sep 2001
Revision 1.1