MT90869AG Zarlink, MT90869AG Datasheet - Page 48

• Manufacturer Part Number: MT90869AG
• Description: Switch Fabric 16K x 16K/8K x 8K 1.8V/3.3V 272-Pin BGA Tray
• Manufacturer: Zarlink

Specifications of MT90869AG

• Package: 272BGA
• Number Of Ports: 64
• Fabric Size: 16K x 16K|8K x 8K
• Switch Core: Non-Blocking|Blocking
• Port Speed: 8.192|4.096|2.048 Mbps
• Operating Supply Voltage: 1.8|3.3 V

12.4
The Backplane Connection Memory (BCM) has 8,192 addresses of 16-bit words. Each address, accessed through
bits A13-A0 of the microprocessor port, is allocated to an individual Backplane output stream and channel. The bit
definition for each 16-bit word is presented in Table 13 for Local-to- Backplane (Non-32Mb/s Mode) and Backplane-
to-Backplane (Non-32 Mb/s Mode) connections, and in Table 14, for Local-to-Backplane (32Mb/s Mode) and
Backplane-to-Backplane (32 Mb/s Mode) connections.
Bit BSRC selects the switch configuration for Local-to-Backplane or Backplane-to-Backplane. When the per-
channel Message Mode is selected (BMM = HIGH), the lower byte of the BCM word (BCAB7-0) will be transmitted
as data on the output stream (BSTo0-31) in place of data defined by the Source Control, Stream Address and
Channel Address bits.
12-8
12-9
7-0
Bit
8-0
Bit
15
14
13
Table 11 - LCM Bits for Local-to-Local and Backplane (Non-32 Mb/s Mode)-to-Local Switching
Backplane Connection Memory Bit Definition
LSRC
LMM
LE
LSAB3-0
LCAB8-0
LSAB4-0
LCAB7-0
Name
Name
Table 12 - LCM Bits for Backplane(32 Mb/s Mode)-to-Local Switching
Source Stream Address Bits
The binary value of these 5 bits represents the input stream number.
Ignored when LMM is set HIGH.
Source Channel Address Bits
The binary value of these 8 bits represents the input channel number when LMM is set
LOW. Transmitted as data when LMM is set HIGH.
Source Control Bit.
When LOW, the source is from the Backplane input port (Backplane Data Memory).
When HIGH, the source is from the Local input port (Local Data Memory).
Ignored when LMM is set HIGH.
Local Message Mode Bit
When LOW, the channel is in Connection Mode.
When HIGH, the channel is in Message Mode.
Local Output Enable Bit
When LOW, the channel may be high impedance, either at the device output or set by an
external buffer, dependent upon the LORS pin. When HIGH, the channel is active.
Source Stream Address Bits.
The binary value of these 4 bits represents the input stream number.
Ignored when LMM is set HIGH.
Channel Address Bits.
The binary value of these 9 bits represents the input channel number, when LMM is LOW.
Bits LCAB7-0 transmitted as data when LMM is set HIGH.
Zarlink Semiconductor Inc.
MT90869
48
Description
Description
Data Sheet