
Multi-Service Access Device For Channelized Interfaces
Telecom Standard Product Data Sheet
Production
Proprietary and Confidential to PMC-Sierra, Inc., and for its Customers’ Internal Use
Document ID: PMC-1990823, Issue 4
587
5. Optionally, reset the performance monitoring counters in all blocks by writing to the S/UNI-
MACH48 Global Performance Monitor Update register. TIP remains high as the
performance monitoring registers are loaded, and is set to a logic zero when the transfer is
complete.
14.18.1 Transmit UL3 Interface Misalignment Recovery
For both single-PHY and multi-PHY transfers on the Transmit UL3 interface, cell alignment is
done on 1-to-0 transition of TENB. That is, TSOC is expected on the same cycle where TENB
has just transitioned to logic 0. Thus, if the upstream device has misalignment between its TENB
and TSOC, the S/UNI-MACH48 will align its cells to the TENB and may give error indications
on its RUNTCELLI (TXPHY Interrupt Status register, 0049H) and/or SOPI interrupt (TXSDQ
SOP Error Port and Interrupt Indication, 0065H). Once the upstream device has realigned its
signals, the S/UNI-MACH48 will realign on the next 1-to-0 transition of TENB.
14.18.2 Receive UL3 Interface Misalignment Recovery
For both single-PHY and multi-PHY transfers on the Receive UL3 interface, cell transfer is
aligned to the RENB signal. Once asserted to logic 0, RENB must not deassert until cycle P11 of
a cell. The S/UNI-MACH48 will not respond to early deassertions of RENB and will continue
transfer of the cell in progress.
To realign the S/UNI-MACH48 to the downstream device, the RENB must remain deasserted for
more than 13 clock cycles. This will guarantee that the S/UNI-MACH48 has completed transfer
of any cell and is ready to reselect a new PHY via RENB.
This means that for a single-PHY application, RENB cannot be tied low with the downstream
device expecting to align using the RSOC output of the S/UNI-MACH48.
14.19 Setting Packet Mode of Operation Over POS-PHY L3
The following sequence of operation should be used to prepare a particular channel(s) for Packet
operation without affecting other channels.
1. Input pin POSL3/UL3B must be tied to logic 1 to enable the POS-PHY L3 system interface at
power-up.
2. Unprovision (disable) all line-side timeslots and system side channels which are to be
changed. This is to be done in the TCAS12, RCAS12, TCFP, RCFP, TTDP, RTDP, RXSDQ,
and TXSDQ blocks. The FIFOs of the corresponding channels will be reset and emptied
when they are unprovisioned.
3. Set the POS_SEL register bits in the TCFP, RCFP, TTDP, RTDP, RXSDQ, and TXSDQ
blocks to logic 1 for the desired POS/HDLC channels.
4. Program the RXPHY servicing algorithm. See Section 14.17 for details.