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PRELIMINARY
INVERSE MULTIPLEXING OVER ATM
PM7340 S/UNI-IMA-8
DATA SHEET
PMC-2001723
ISSUE 3
INVERSE MULTIPLEXING OVER ATM
PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA, INC., AND FOR ITS CUSTOMERS’ INTERNAL USE
232
RDAT IMA Group Context Memory
The RDAT IMA Group Context Memory contains state information maintained by
the cell reader. This memory contains state information for up to 4 IMA groups.
The only field in this structure that must be programmed is the vphy_id. Each
record is 32 bits wide by 4 words, and is addressed by the group tag.
MEM_ADDR = (Group Tag X 4) + Word Offset
Table 28
RDAT IMA Group Context Record
Word Bits
Parameter
Description
0
31:16 vphy_id
Virtual PHY ID. This identifies the address that will
be prepended to all cells as they are written to the
RXAPS FIFO. For multiple channel mode, the
least significant 5 bits determine the destination
channel of the RXAPS FIFO for this IMA group.
For single channel mode, the least significant 7
bits must uniquely identify a channel (legal values
of 0-7).
15:0
Reserved.
1
31:16
Reserved
15:0
read_ptr
Current read pointer for the delay compensation
buffers associated with this group. The most
significant bits represent an extension of the
pointer, which is based on the IMA frame
sequence number. This field is initialized at link
addition using the DCB depth command (with the
initiate bit set).
2
31:0
Reserved
3
31:0
Reserved.
RDAT TC Context Memory
The RDAT TC Context Memory contains state information maintained by the cell
reader. This memory contains state information for up to 8 TC connections. Each
record is 32 bits wide by 1 word, and is address by the TC tag.