MT90870 Zarlink Semiconductor, Inc., MT90870 Datasheet - Page 37

• Manufacturer Part Number: MT90870
• Description: Flexible 12k Digital Switch (F12kDX)
• Manufacturer: Zarlink Semiconductor, Inc.

Preliminary Information
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
7-0
Bit
7-0
Bit
A8-A0
A14
Memory Address Mappings
Backplane Data Memory Bit Definition
Local Data Memory Bit Definition
Table 8 - Address Map for Data and Connection Memory Locations (A14=1)
Reserved
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 32.768Mb/s.
3. Channels 0 to 31 are used when serial stream is at 2.048Mb/s.
4. Channels 0 to 63 are used when serial stream is at 4.096Mb/s.
5. Channels 0 to 127 are used when serial stream is at 8.192Mb/s.
6. Channels 0 to 255 are used when serial stream is at 16.384Mb/s.
7. Channels 0 to 511 are used when serial stream is at 32.768Mb/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
Local Data Memory
Local Input Channel Data
Table 10 - Local Data Memory (LDM) Bits
Set to a default value of 0
Description
Description
Description
MT90870
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