
PRELIMINARY
INVERSE MULTIPLEXING OVER ATM
PM7341 S/UNI-IMA-84
DATASHEET
PMC-2000223
ISSUE 4
INVERSE MULTIPLEXING OVER ATM
PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA, INC., AND FOR ITS CUSTOMERS’ INTERNAL USE
358
12.4 IMA_LAYER Configuration
12.4.1 Indirect access to internal memory tables
The IMA-Layer operations are configured by internal memory tables. The access
to these tables is by indirect access. The following procedure applies for the
indirect accesses in the RIPP, RDAT, TIMA, TXIDCC, and RXIDCC blocks.
12.4.1.1
Write accesses
The indirect write access procedure is as follows:
1) Wait until the “BUSY” bit in the
Block
Indirect Memory Access Control
Register is clear.
2) Once the BUSY bit is clear, write to the
Block
Data Indirect Data
Register(s) to specify the data to be written for that link.
3) Next, write into the
Block
Indirect Memory Address register specifying the
address that is about to be configured and then write
Block
Indirect Memory
Command register to specify the table to be accessed and whether the
access is to be a write or a read access, by clearing or setting the RWB bit in
this register. Note that is some instances, the
Block
Indirect Memory Address
register is combined with the
Block
Indirect Memory Access Control Register
12.4.1.2
Read Accesses
The indirect read access procedure is as follows:
1) Wait until the “BUSY” bit in the
Block
Indirect Memory Access Control
Register is clear.
2) Once the BUSY bit is clear, write into the
Block
Indirect Memory Address
register specifying the address that is about to be configured and then write
Block
Indirect Memory Command register to specify the table to be accessed
and whether the access is to be a write or a read access, by clearing or
setting the RWB bit in this register. Note that is some instances, the
Block
Indirect Memory Address register is combined with the
Block
Indirect Memory
Access Control Register