XTNETA1570MFP datasheet(56/68 Pages) TI1

56 / 68 page

TNETA1570

ATM SEGMENTATION AND REASSEMBLY DEVICE

WITH INTEGRATED 64BIT PCIHOST INTERFACE

SDNS033B − JUNE 1995 − REVISED MAY 1996

POST OFFICE BOX 655303

• DALLAS, TEXAS 75265

POST OFFICE BOX 1443

• HOUSTON, TEXAS 77251−1443

PRINCIPLES OF OPERATION

64-bit PCI cell-payload reads

The top-down order of the following chart represents the time order of 64-bit word reads by the TNETA1570.

PCI ADDRESS

PCI ADDRESS BITS

×10

×18

×20

The cell data above is transmitted from the segmentation unit’s UTOPIA bus in the byte order 0, 2, 3, 4, 5, 6,

7, 8, 9 . . .

big-endian configuration

There are two scenarios for TNETA1570 cell-payload PCI reads from the host memory when the TNETA1570

is configured as a big-endian device. These are 32-bit PCI cell-payload reads and 64-bit PCI cell-payload reads.

32-bit PCI cell-payload reads

The top-down order of the following chart represents the time order of 32-bit word reads by the TNETA1570.

PCI ADDRESS

PCI ADDRESS BITS

×10

×14

×18

The cell data above is transmitted from the segmentation unit’s UTOPIA bus in the byte order 0, 1, 2, 3, 4, 5, . . .

64-bit PCI cell-payload reads

The following table shows the PCI bus byte/address ordering when cell-payload bytes are input to the

reassembly UTOPIA port in order 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 . . .

The top-down order of the following chart represents the time order of 64-bit word reads by the TNETA1570.

PCI ADDRESS

PCI ADDRESS BITS

×10

×18

×20

The cell data above is transmitted from the segmentation unit’s UTOPIA bus in the byte order 0, 1, 2, 3, 4, 5,

6, 7, 8, 9 . . .

XTNETA1570MFP Datasheet(PDF) 56 Page - Texas Instruments