XRT83L314 Datasheet, PDF (40/84 Pages) Exar Corporation – 14-CHANNEL T1/E1/J1 LONG-HAUL/SHORT-HAUL LINE INTERFACE UNIT

XRT83L314
14-CHANNEL T1/E1/J1 LONG-HAUL/SHORT-HAUL LINE INTERFACE UNIT
REV. 1.0.0
4.2 84-Channel T1/E1 Multiplexer/Mapper Applications
The XRT83L314 has the capability of providing the necessary chip selects for multiple 14-channel LIU devices.
The LIU is responsible for selecting itself, up to 5 additional LIU devices, or all 6 devices simultaneously for
permitting access to internal registers. The state of the chip select output pins is determined by a chip select
decoder controlled by the 3 MSBs of the address bus ADDR[10:8]. Only one LIU (Master) requires the
ADDR[10:8]. The other 5 LIU devices use the 8 LSBs for the direct address bus ADDR[7:0]. Figure 35 is a
simplified block diagram of connecting six 14-channel LIU devices for 84-channel applications. Selection of
the chip select outputs using ADDR[10:8] is shown in Table 13.
FIGURE 35. SIMPLIFIED BLOCK DIAGRAM OF AN 84-CHANNEL APPLICATION
Master
CS[4:0]
XRT83L314
1
CS
Slave
XRT83L314
2
CS
Slave
XRT83L314
3
CS
Slave
XRT83L314
4
CS
Slave
XRT83L314
5
CS
Slave
XRT83L314
6
Data [7:0]
Address A[7:0]
Chip Address A[10:8]
TABLE 13: CHIP SELECT ASSIGNMENTS
ADDR[10:8]
ACTIVE CHIP SELECT
0h (000)
Current Device (Master)
1h (001)
Chip 1
2h (010)
Chip 2
3h (011)
Chip 3
4h (100)
Chip 4
5h (101)
Chip 5
6h (110)
Reserved
7h (111)
All Devices Active
36