W6691CD WINBOND [Winbond], W6691CD Datasheet - Page 90

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

XACT
"0": transmitter is active, 64 KHz clock is provided.
"1": transmitter is inactive, clock is LOW to save power.
This bit is read/write. Read operation returns the previously written value.
Note: The transmitter is deactive after hardware reset or software reset.
B1_128
"1": Both B1 and B2 channels in layer 1 are combined into single layer 2 channel. The layer 2 B1 channel can
operates in transparent mode or extended transparent mode and layer 2 B2 channel is not used.
"0": Both B1 and B2 channels in layer 1 are not combined.
This bit is read/write. Read operation returns the previously written value.
SW56
0: The data rate in B1 channel is 64 kbps.
1: The data rate in B1 channel is 56 kbps. The most significant bit in each octet is fixed at "1".
Note: In 56 kbps mode, only transparent mode can be used.
FTS1-0
These two bits determine the B1 channel receive and transmit FIFO's threshold setting. An interrupt is
generated when the number of received data or the number of vacancies in XFIFO reaches the threshold
value.
8.11.5 B1_ch Extended Interrupt Register B1_EXIR
Value after reset: 00H
7
0
Transmitter Active
Switch 56 Traffic
RMR
FIFO Threshold Select
128K Mode
6
FTS1
0
0
1
1
RME
5
FTS0
0
1
0
1
RDOV
4
Threshold (byte)
Not allowed
Reserved
3
0
64
96
2
0
90
XFR
1
Read_clear
XDUN
0
Preliminary W6691
Publication Release Date: Sep 2001
Address 56H
Revision 1.1