PM7344 S/UNI-MPH
DATA SHEET
PMC-950449
ISSUE 6
MULTI-PHY USER NETWORK INTERFACE
Pin Name
Type
Pin Function
No.
RCAMPH
I/O
82
Receive Multi-Phy Cell Available (RCAMPH).
The RCAMPH signal is output on this pin when
input MPHEN is high. This signal indicates
when a cell is available in the receive FIFO for
the port selected by RRA[1:0]. RCAMPH can be
configured to be deasserted when either zero or
four bytes remain in the selected/addressed
FIFO. RCAMPH will thus transition low on the
rising edge of RFCLK after the 53rd or 48th byte
has been output if the PHY being polled is the
same as the PHY in use .
RRDENB[4]
Receive Read Enable PHY #4 (RRDENB[4]).
The RRDENB[4] signal is input on this pin when
input MPHEN is low. RRDENB[4] is used to
initiate reads from the receive FIFO of PHY #4.
When sampled low using the rising edge of
RFCLK (and the remaining three RRDENBs
remain high), a byte is read from PHY #4'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[4] 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[4]
at anytime it is unable to accept another byte.
RDAT[0]
RDAT[1]
RDAT[2]
RDAT[3]
RDAT[4]
RDAT[5]
RDAT[6]
RDAT[7]
Tristate
Output
89
90
91
92
93
94
95
96
Receive Cell Data Bus (RDAT[7:0]). This bus
carries the ATM cell octets that are read from
the selected receive FIFO. RDAT[7:0] is
updated on the rising edge of RFCLK and is
tristated when RRDENB[n]/RRDMPHB is high.
PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA, INC., AND FOR ITS CUSTOMERS’ INTERNAL USE
29
PMC [ PMC-SIERRA, INC ]
