S/UNI®-JET Data Sheet
Released
Pin Name
Type
Pin
No.
Function
TADR[2]
TADR[1]
TADR[0]
Input
F18
F19
F20
The Transmit Address (TADR[2:0]) bus is used for
device selection and device polling in accordance with
the Utopia Level 2 standard.
When TADR[2:0] is set to the same value as the
PHY_ADR[2:0] inputs than the transmit interface of this
S/UNI-JET is either being selected or polled.
Note: The null-PHY address 7H is an invalid address and
cannot be used to select the S/UNI-JET.
TADR[2:0] is sampled on the rising edge of TFCLK.
TCA
Output
H19
The Transmit Multi-PHY Cell Available (TCA) signal
indicates when a cell is available in the transmit FIFO for
the device selected by TADR[2:0].
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 device being polled is the same
as the selected device.
To reduce FIFO latency, the FIFO depth at which TCA
indicates "full" can be set to one, two, three, or four cells.
Note: Regardless of what fill level TCA is set to indicate
"full" at, the transmit cell processor can store four
complete cells.
TCA is tri-stated when either the null-PHY address (7H)
or an address not matching the address space set by
PHY_ADR[2:0] is latched (by TFCLK) from the
TADR[2:0] inputs.
The polarity of TCA (with respect the the description
above) is inverted when the TCAINV register bit is set to
logic one.
TFCLK
Input
E20
The Transmit FIFO Write Clock (TFCLK) is used to write
ATM cells to the four-cell transmit FIFOs. TFCLK cycles
at a 52 MHz or lower instantaneous rate.
Proprietary and Confidential to PMC-Sierra, Inc., and for its Customers’ Internal Use
Document ID: PMC-1990267, Issue 3
45
PMC [ PMC-SIERRA, INC ]
