PM7344 Datasheet, PDF (42/293 Pages) PMC-Sierra, Inc – SATURN QUAD T1/E1 MULTI-PHY USER NETWORK INTERFACE DEVICE

DATA SHEET
PMC-950449
ISSUE 6
PM7344 S/UNI-MPH
MULTI-PHY USER NETWORK INTERFACE
Pin Name Type
RRDMPHB Input
RRDENB[1]
Pin Function
No.
79 Receive Multi-Phy Read Enable (RRDMPHB).
The RRDMPHB signal is available on this pin
when input MPHEN is high. RRDMPHB is used
to initiate reads from the receive FIFOs. When
sampled low using the rising edge of RFCLK, a
byte is read from the receive FIFO selected by
the RRA[1:0] address bus (if one is available)
and output on bus RDAT[7:0]. When sampled
high using the rising edge of RFCLK, no read is
performed and RDAT[7:0] and RSOC are
tristated. RRDMPHB must operate in
conjunction with RFCLK to access the FIFOs at
a high enough instantaneous rate as to avoid
FIFO overflows. The ATM layer device may
deassert RRDMPHB at anytime it is unable to
accept another byte.
Receive Read Enable PHY #1 (RRDENB[1]).
The RRDENB[1] signal is available on this pin
when input MPHEN is low. RRDENB[1] is used
to initiate reads from the receive FIFO of PHY
#1. When sampled low using the rising edge of
RFCLK (and the remaining three RRDENBs
remain high), a byte is read from PHY #1's
synchronous FIFO and output on bus RDAT[7:0]
if one is available. When sampled high using
the rising edge of RFCLK, no read is performed
and RDAT[7:0] and RSOC are tristated.
RRDENB[1] must operate in conjunction with
RFCLK to access the FIFOs at a high enough
instantaneous rate as to avoid FIFO overflows.
The ATM layer device may deassert RRDENB[1]
at anytime it is unable to accept another byte.
PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA, INC., AND FOR ITS CUSTOMERS’ INTERNAL USE 26