PM5352 datasheet(23/77 Pages) PMC

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PM5352 S/UNI STAR

DATA SHEET

PMC-1990421

ISSUE 2

SATURN USER NETWORK INTERFACE 155 (STAR)

PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA, INC., AND FOR ITS CUSTOMERS’ INTERNAL USE

Pin Name

Type

No.

Function

TCA

Output

(ATM)

J23

UTOPIA Transmit multi-PHY Cell Available (TCA)

The TCA signal indicates when a cell is available in

the transmit FIFO for the port polled by TADR[2:0]

when TENB is asserted. When high, TCA indicates

that the transmit FIFO is not full and a complete cell

may be written. When TCA goes low, it can be

configured to indicate either that the transmit FIFO

is near full or that the transmit FIFO is full. TCA will

transition low on the rising edge of TFCLK after the

Payload word 19 (TCALEVEL0=0) or 23

(TCALEVEL0=1) is sampled if the PHY being polled

is the same as the PHY in use. To reduce FIFO

latency, the FIFO depth at which TCA indicates

"full" can be set to one, two, three or four cells.

Note that regardless of what fill level TCA is set to

indicate "full" at, the transmit cell processor can

store 4 complete cells.

TCA is tri-stated when either the null-PHY address

(0x7) or an address not matching the address set

by PHY_ADR[2:0] is latched from the TADR[2:0]

inputs when TENB is high.

TCA is updated on the rising edge of TFCLK.

PM5352 Datasheet(PDF) 23 Page - PMC-Sierra, Inc