MT90820AL Zarlink, MT90820AL Datasheet - Page 23

• Manufacturer Part Number: MT90820AL
• Description: Switch Fabric 2K x 2K/1K x 1K/512 x 512 131.072Mbps 5V 100-Pin MQFP Tray
• Manufacturer: Zarlink

Specifications of MT90820AL

• Package: 100MQFP
• Number Of Ports: 16
• Fabric Size: 2K x 2K|1K x 1K|512 x 512
• Switching Bandwidth: 131.072 Mbps
• Switch Core: Non-Blocking
• Port Speed: 2.048|4.096|8.192 Mbps
• Operating Supply Voltage: 5 V

Serial Input Frame Alignment Evaluation
The MT90820 is capable of performing frame alignment evaluation. The frame pulse under evaluation is connected
to the FE (frame measurement) pin. An external multiplexer is required to selected one of the frame pulses related
to the different input streams. Figure 6 gives an example of performing measurement for 16 frame pulses can be
performed.
Wide Frame Pulse (WFP) Frame Alignment Mode
When the device is the wide frame pulse mode, the device can operate in the HMVIP and MVIP-90 environment if
the input data streams are sampled at 3/4 bit time. When input data stream are sampled at half-bit time as specified
in the HMVIP and MVIP-90 standard, the device can only operate with data rate of 2 Mb/s. Refer to the ST-BUS
output delay parameter, t
Note:
1. Use the external mux to select one of the serial frame pulses.
2. To start a measurement cycle, set the Start Frame Evaluation (SFE) bit in the IMS register low for at least 1 frame.
3. Frame evaluation starts when the SFE bit is changed from low to high.
4. Two frames later, the Complete Frame Evaluation (CFE) bit of the Frame Alignment Register (FAR) changes from low to high to
signal the CPU that a valid offset measurement is ready to be read from bit [11:0] of the FAR register.
5. The SFE bit must be set to zero before a new measurement cycle started.
IN
16 Streams
16 Streams
Figure 6 - Serial Input Frame Alignment Evaluation for Various Frame Pulses
FP STi15
FP STi0
FP STi1
FP STi2
Figure 5 - Switch Matrix with Serial Stream at Various Bit Rates
SOD
STi0
STi1
STi2
STi15
, as specified in the AC Electrical Characteristic table.
External
Mux
MT90820
MT90820
MT90820
MT90820
#1
#2
#3
#4
input
Zarlink Semiconductor Inc.
FE
Frame Alignment
Evaluation circuit
MT90820
MT90820
CLK
23
FP
16 Streams
16 Streams
Timing Source
Central
OUT
2.048 Mb/s
4.096 Mb/s
8.192 Mb/s
(IN/OUT)
STo[0:15]
Bit Rate
1,024 - Channel Switch
2,048 - Channel Switch
4,096 - Channel Switch
Switch Matrix
Size of
Data Sheet