W6691CD WINBOND [Winbond], W6691CD Datasheet - Page 42

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

4. B2SW1 / B2SW0 B2 channel Switch
These two bits determine B2 channel switch among PCM port , Layer1/GCI and Layer2.
00: Select B2 channel switch between Layer2 and Layer1/GCI.
01: Select B2 channel switch between Layer1/GCI and PCM.
10: Select B2 channel switch between PCM and Layer2.
5. B1SW1 / B1SW0
These two bits determine B1 channel switch among PCM port , Layer1/GCI and Layer2.
00: Select B1 channel switch between Layer2 and Layer1/GCI.
01: Select B1 channel switch between Layer1/GCI and PCM.
10: Select B1 channel switch between PCM and Layer2.
7.4 PCM Port
synchronization clocks (PFCK1-2) are 8 kHz and the bit synchronization clock (PBCK) is 1.536 MHz.
7.5 D Channel HDLC Controller
formats are shown below.
There are two PCM ports in W6691. Data is valid when respective PFCK is HIGH. The frame
There are two HDLC protocols that are used for ISDN layer 2 functions : LAPD and LAPB. Their frame
PXC
0
1
PCM1
PCM1
B1 channel Switch
B1, PCM2
B2, PCM2
Connection
B2
B1
42
Preliminary W6691
Publication Release Date: Sep 2001
Revision 1.1