tdat04622 ETC-unknow, tdat04622 Datasheet - Page 129

• Manufacturer Part Number: tdat04622
• Description: Tdat Sonet/sdh 155/622/2488 Mbits/s Data Interfaces
• Manufacturer: ETC-unknow

Data Sheet
May 2001
Agere Systems Inc.
Line Interface
LVPECL I/O Termination and Load Specifications
The input common mode range for LVPECL differential buffers is from 1 V to 2.75 V; and the swing needs to be at
least 300 mV. So basically what it means is the lowest voltage on the input should be no lower than (1 V – 0.150 V)
and the highest voltage on the input shouldn’t be more than (2.75 V + 0.150 V). So if the differential swing is
800 mV, then the common mode range would be 2.5 V down to 1.25 V. This is all for 3 V buffers.
Interface Description
Microprocessor Interface
This device is equipped with a generic 16-bit microprocessor interface that allows operation with most commer-
cially available microprocessors. Input MPMODE is used to configure this interface into one of two possible modes
(synchronous or asynchronous). In synchronous mode, the microprocessor interface can operate at speeds from
1 MHz up to 66 MHz.* In asynchronous mode, the internal 78 MHz system clock is used to operate this interface.
Table 31. MPU Modes
The host interface is designed to connect directly to a commonly used asynchronous or synchronous host bus.
The interface to this block includes a separate clock, MPCLK, which is used in the synchronous interface mode.
The interface is only a slave on the host bus. There is no posting of writes in the host interface; all registers are
directly accessible. The microprocessor interface pins use 3.3 V (5 V, TTL-tolerant) CMOS I/O levels. The micro-
processor interface timing specifications are given in the Interface Timing Specifications section (see Table 163—
Table 166, pages 257—263).
* All status counters must be read within the 1-second time window of the PMRST. If this is not the case, counter values will be l ost.
MPMODE
0
1
(continued)
Async
Mode
Sync
MPCLK, CS, INT, D[15:0], A[15:0], ADS, R/W, DT
CS, INT, D[15:0], A[15:0], ADS, R/W, DS, DT
Microprocessor Interface Signals
(continued)
155/622/2488 Mbits/s Data Interface
TDAT042G5 SONET/SDH
101