![](http://datasheet.mmic.net.cn/330000/PM7323_datasheet_16444372/PM7323_44.png)
STANDARD PRODUCT
PM7323 RCMP-200
DATASHEET
PMC-960543
ISSUE 2
ROUTING CONTROL, MONITORING, & POLICING
200 MBPS
Proprietary and Confidential to PMC-Sierra, Inc.
and for its Customer’s Internal Use.
33
The RCMP-200 is a bus master and services the PHY devices in one of two
ways: direct status arbitration or address line polling. For direct status arbitration,
the RCMP-200 monitors cell available signals (ICA[4:1]) from to up four physical
(PHY) layer devices and generates write enables (WRENB[4:1]) in response. For
address line polling, ICA[1] and IWRENB[1] are shared between up to 32 PHY
devices and signals IADDR[4:0] and IAVALID are used to address the latter
individually. The RCMP-200 performs round-robin polling of the PHY devices to
determine which have available cells. The RCMP-200 will read an entire cell
from one PHY device before accessing the next PHY device. No fixed cell slots
exist, but instead the RCMP-200 maximizes throughput by servicing a PHY
device as soon as the bus is free and PHY device's cell available signal is
asserted.
All input FIFO signals, ISOC, IWRENB[4:1], ICA[4:1], IADDR[4:0], IAVALID,
IPRTY and IDAT[7:0] are either sampled or updated on the rising edge of the
IFCLK clock input.
9.2
VC Identification
The RCMP-200 makes use of a flexible approach to identify incoming cells and
to determine which record in the VC Table they are associated with. The RCMP-
200 is able to identify each cell's VC by searching the VC Search Table (see
Table 6) using selected portions of the cell header, prepend, postpend along
with the cell's PHY address. To do this, the RCMP-200 creates an internal
Routing Word which is the concatenation of the cell header, cell prepend and
cell postpend. The RCMP-200 is programmed to select portions of the Routing
Word plus the PHY address to create a VC Search Key. The VC Search key,
therefore, consists of portions of the cell's header, prepend, postpend and SCI-
PHY address. See Figure 3.
Figure 3 is not intended to imply any restrictions on the positioning of Field A and
Field B. These fields may occur any where within the appended octets or the
ATM header. The Primary Key and Secondary Key may also intersect.