W6692 Datasheet, PDF (38/104 Pages) Winbond – PCI Bus ISDN S/T-Controller

Preliminary Data Sheet
7.3 Serial Interface Bus
W6692 PCI ISDN S/T-Controller
The 192 kbps S/T interface signal consists of two B channels (64 kbps each), one D channel (16 kbps) and other control
signals. The multiplexing/demultiplexing functions are carried out in the Serial Interface Bus (SIB) block. In addition, the B1
and B2 channels can be individually set to carry 64 kbps or 56 kbps traffic.
7.4 B Channel Switching
Each B channel in S/T bus or U transceiver can be individually programmed to connect to one of the three data ports : B
channel HDLC controller , PCM port 1 or PCM port 2. In addition, the PCM ports can be programmed to connect to the B
channel HDLC controller for voice recording/ retrieving from main memory in answering machine applications. In this case,
only extended transparent mode can be used.
The switching matrix is controlled by PXC bit in PCTL register and BSW1-0 bits in B1_MODE and B2_MODE registers as
follows :
B1
Layer 1
01
0
/GCI
00 ₁₀
1
PCM
TX/RX
Layer 1
/GCI
HDLC/
Layer 2
B2
01
00 10
1
0
PCM2
TX/RX
HDLC/Layer 2
BSW1-0 bits
PXC bit
A special mode is provided (BSW1-0 = 11B) in which case the PCM port can receive data from layer 1 and the HDLC receiver
can receive data from PCM port simultaneously. Here are the setting values of possible switching combinations shown as below.
PCM1 Receive Table
PXC B1_SW[1:0] B2_SW[1:0]
0
00
xx
0
01
xx
0
10
xx
0
11
xx
1
xx
00
1
xx
01
1
xx
10
1
xx
11
PCM1 Rx
L1_B1
L1_B1
L2_B1
PCM1
L1_B2
L1_B2
L2_B2
PCM2
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Publication Release Date: Sep 30, 1999
Revision 0.9