PM7375 Datasheet, PDF (383/430 Pages) PMC-Sierra, Inc – ATM SAR and PHY Processor for PCI Bus

DATA SHEET
PMC-931127
ISSUE 6
PM7375 LASAR-155
LOCAL ATM SAR & PHYSICAL LAYER
14.2 Multipurpose Port Interface
14.2.1.1 Fig. 14.4 Receive Cell Extraction Port (RXPHYBP=0)
SYSCLK
••••
RFIFOFB
RDAT[7:0]
••••
H1 H2 •••• P44 P45 P46 P47 P48
RRDENB
••••
RSOC
••••
H1 H2
The Receive Cell Extract Port (RXPHYBP=0) figure illustrates the LASAR-155's
Receive Multipurpose port when configured to source cell to an external device (i.e.
a Synchronous FIFO). When RXPHYBP is forced low, pins RSOC and RDAT[7:0]
become outputs.
When the active low Receive FIFO Full input, RFIFOFB is deasserted, the
LASAR-155 assumes that an external device can accept a byte and forces output
RRDENB low to indicate a byte is available on outputs, RDAT[7:0]. At anytime, the
external device can throttle back the reception of words by deasserting RFIFOFB.
However since the LASAR-155's does not have internal cell storage, throttling is not
recommended. If throttling results in an internal overflow, the LASAR-155 will abort
bursting out the current cell.
PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA, INC., AND FOR ITS CUSTOMERS’ INTERNAL USE 367