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S/UNI-ATLAS-3200 Telecom Standard Product Data Sheet
Preliminary
Proprietary and Confidential to PMC-Sierra, Inc., and for its Customers’ Internal Use
Document ID: PMC-1990553, Issue 4
409
14.2.1 Ingress UL3 Interface
In the Ingress direction, the S/UNI-ATLAS-3200 provides an Rx Link interface on the input
(PHY) side, and an Rx PHY interface on the output (system) side. Selection of ingress vs. egress
mode and POS vs UL3 signalling must be performed at startup.
Figure 38 shows the format of an Rx UTOPIA transfer. On the input (RxLink) side the ‘x’ in the
signals is a ‘L’; on the output (RxPHY) side the ‘x’ is a ‘P’.
The Rx interface in UL3 is controlled by the downstream ATM Layer (aka Link Layer) device,
which polls the PHY layer device, and uses RxP_RDENB to select PHYs for transfer, and enable
the transfer. Once a transfer has been initiated, it must be completed.
Figure 38 Ingress UTOPIA Logical Timing
1
2
3
4
5
6
7
8
9
10
PHY07
PHY08
PHY09
PHY00
PHY02
PHY03
PHY04
DAT12
DAT11
DAT10
DAT9
PHY05
PHY06
PHY06
H1
DAT0
DAT1
DAT2
DAT3
PHY08
PHY07
PHY06
RxP_CLK
RxP_ADDR[5:0]
RxP_CLAV
RxP_RDENB
RxP_DAT[31:0]
RxP_SOC
RxP_PAR
The Receive Link Layer interface is a regular UL3 MPHY interface. The Receive PHY layer
interface, however, can operate either as a MPHY interface, or as a single-PHY interface. The
single-PHY interface, selected via the Servicing Override bit in the RxP Configuration register,
allows the S/UNI-ATLAS-3200 to interface to a MPHY device on its input, and to an non-PHY-
aware, single-PHY switch fabric on the other. In this case, cells will be drawn from the internal
PHY queues as determined by the RxP Calendar. This operation is transparent to the switch,
which sees a single-PHY interface.
RxLink UTOPIA Logical Timing
In the ingress direction, the S/UNI-ATLAS-3200 input cell/packet interface acts as a Receive
ATM Layer device, and the upstream device acts as a PHY Layer device, for the purposes of
UTOPIA Level 3 cell transfer.