
PM7346 S/UNI-QJET
DATASHEET
PMC-960835
ISSUE 6
SATURN QUAD USER NETWORK INTERFACE FOR J2, E3, T3
PMC-SIERRA, INC. PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA INC., AND ITS CUSTOMERS’ INTERNAL USE
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being received from PHY “D,” and the DRCA[D] signal shows how the DRCA[x]
signals behave based on the value of the RCALEVEL0 register bit(s). The ATM
Layer device is not restricted in its polling order. The PHY associated with
address "A" indicates it does not have a cell available, but PHY "B" indicates that
it does. As a result, the ATM Layer places address "B" on RADR[4:0] the cycle
before RENB is asserted to select PHY "B" as the next cell source. In this
example, PHY "C"s status is ignored. The ATM Layer device is not constrained
to select the latest PHY polled. As soon as the cell transfer is started, the polling
process may be restarted. The data on RDAT (W1, W2, ...) may be 8-bit or 16-
bits wide, depending on the setting of the ATM8 input.
During multi-PHY operation, several PHY layer devices share the RDAT[15:0],
RSOC, RPRTY, and RCA signals. As a result, these signals must be tri-stated in
all PHY devices which have not been selected for reading or polling by the ATM
Layer. Selection of which PHY layer device is being read is made by the value
on RADR[4:0] the cycle before RENB is asserted and affects the RDAT[15:0],
RSOC, and RPRTY signals. The value of RADR[4:0] selects the PHY being
polled for the RCA signal, and all devices not corresponding to this address must
tri-state its RCA output. These multi-PHY operations are directly supported by
the S/UNI-QJET.