PM5345 S/UNI-155
DATA SHEET
PMC-930305
ISSUE 4
SATURN USER NETWORK INTERFACE
Pin Name Type
Pin
Function
No.
TSEN
Input
109
The tristate enable (TSEN) input selects the
configuration of the receive datapath
(RDAT[15:0]). When TSEN is tied high,
RDAT[15:0] normally operates as a tristate bus
controlled by RRDB. When RRDB is high,
RDAT[15:0] is tristated. When RRDB is low,
RDAT[15:0] is enabled. When TSEN is tied
low, RDAT[15:0] normally operates as an
output bus, and is always enabled, regardless
of the state of RRDB
BUS8
RRDB
Input
Input
110
111
The bus width select (BUS8) input selects the
transmit and receive datapath widths. When
BUS8 is tied high, a 9-bit interface consisting
of a start of cell indication, and an 8-bit octet
bus is selected. When BUS8 is tied low, a 17-
bit interface consisting of a start of cell
indication, and a 16-bit word bus is selected.
The active low receive read strobe (RRDB) is
used to read ATM cells from the receive FIFO.
When active, RRDB must cycle at a 25 MHz or
lower instantaneous rate, but at a high enough
rate to avoid FIFO overflow. RSOC is updated
on the rising edge of RRDB. RDAT[15:0] are
updated on the falling edge of RRDB.
PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA, INC., AND FOR ITS CUSTOMERS’ INTERNAL USE
25
PMC [ PMC-SIERRA, INC ]
