PM7346 S/UNI-QJET
DATASHEET
PMC-960835
ISSUE 6
SATURN QUAD USER NETWORK INTERFACE FOR J2, E3, T3
Pin Name
Type
Pin No. Function
TCA
Output H19
Transmit Multi-Phy Cell Available (TCA).
The TCA signal indicates when a cell is
available in the transmit FIFO for the port
selected by TADR[4:0]. When high, TCA
indicates that the corresponding 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
corresponding transmit FIFO is near full or
that the corresponding transmit FIFO is
full. TCA will transition low on the rising
edge of TFCLK which samples Payload
byte 43 (TCALEVEL0=0) or 47
(TCALEVEL0=1) for the 8-bit interface
(ATM8=1), or the rising edge of TFCLK
which samples Payload word 19
(TCALEVEL0=0) or 23 (TCALEVEL0=1)
for the 16-bit interface (ATM8=0) 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 (1FH) or an address not matching
the address space set by PHY_ADR[2:0]
is latched (by TFCLK) from the TADR[4:2]
inputs.
The polarity of TCA (with respect the the
description above) is inverted when the
TCAINV register bit is set to logic 1.
PMC-SIERRA, INC. PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA INC., AND ITS CUSTOMERS’ INTERNAL USE 44
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