PM7344 S/UNI-MPH
DATA SHEET
PMC-950449
ISSUE 6
MULTI-PHY USER NETWORK INTERFACE
Pin Name
Type
Pin Function
No.
RRA[1]
Input
81
Receive Read Address MSB (RRA[1]). The
RRA[1] signal is available on this pin when input
MPHEN is high. RRA[1] is used (along with
RRA[0]) to select the FIFO (and hence port) that
is read from using the RRDMPHB signal.
RRA[1] is sampled on the rising edge of RFCLK
together with RRDMPHB.
RRDENB[3]
Receive Read Enable PHY #3 (RRDENB[3]).
The RRDENB[3] signal is available on this pin
when input MPHEN is low. RRDENB[3] is used
to initiate reads from the receive FIFO of PHY
#3. When sampled low using the rising edge of
RFCLK (and the remaining three RRDENBs
remain high), a byte is read from PHY #3'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[3] 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[3]
at anytime it is unable to accept another byte.
PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA, INC., AND FOR ITS CUSTOMERS’ INTERNAL USE
28
PMC [ PMC-SIERRA, INC ]
