MT90870AG Zarlink, MT90870AG Datasheet - Page 48

• Manufacturer Part Number: MT90870AG
• Description: Switch Fabric 12K x 12K/8K x 4K 1.8V/3.3V 272-Pin BGA Tray
• Manufacturer: Zarlink

Specifications of MT90870AG

• Package: 272BGA
• Number Of Ports: 32
• Fabric Size: 12K x 12K|8K x 4K
• Switch Core: Non-Blocking|Blocking
• Port Speed: 2.048|4.096|8.192|16.384 Mbps
• Operating Supply Voltage: 1.8|3.3 V

12.0
The device contains two data memory blocks, one for received Backplane data and one for received Local data. For
all data rates the received data is converted to parallel format by internal serial to parallel converters and stored
sequentially in the relevant data memory.
12.1
The 8-bit Backplane Data Memory (BDM) has 8,192 positions. The locations are associated with the Backplane
input streams and channels. The address bits (A13:0) of the microprocessor define the addresses of the streams
and the channels. The BDM is configured as follows:
12.2
The 8-bit Local Data Memory (LDM) has 4,096 positions. The locations are associated with the Local input streams
and channels. The address bits of the microprocessor define the addresses of the streams and the channels. The
LDM is configured as follows:
Address Bit
15-8
15-8
A13-A9
Bit
7-0
7-0
Bit
A8-A0
A14
Local Data Memory Bit Definition
Backplane Data Memory Bit Definition
Memory Address Mappings
Reserved
Table 8 - Address Map for Data and Connection Memory Locations (A14=1)
Name
Selects memory or register access
Stream address (0-31)
Channel address (0-511)
Notes:
1. Bit A14 must be high for accessing to data and connection memory positions. Bit A14 must
be low for accessing registers.
2. Streams 0 to 15 are used when the Backplane serial streams are at 32.768 Mb/s.
3. Channels 0 to 31 are used when serial stream is at 2.048 Mb/s.
4. Channels 0 to 63 are used when serial stream is at 4.096 Mb/s.
5. Channels 0 to 127 are used when serial stream is at 8.192 Mb/s.
6. Channels 0 to 255 are used when serial stream is at 16.384 Mb/s.
7. Channels 0 to 511 are used when serial stream is at 32.768 Mb/s.
Reserved
BDM
Name
LDM
Set to a default value of 0
Backplane Data Memory
Backplane Input Channel Data
Table 9 - Backplane Data Memory (BDM) Bits
Set to a default value of 0
Local Data Memory
Local Input Channel Data
Table 10 - Local Data Memory (LDM) Bits
Zarlink Semiconductor Inc.
MT90870
48
Description
Description
Description
Data Sheet