Proprietary and Confidential to PMC-Sierra, Inc and for its Customers
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Internal Use
Document ID: PMC-2010146, Issue 4
91
PM2329 ClassiPI Network Classification Processor Datasheet
4.2.2.6 E-RAM Indirect Data Register Set (EIDR0; 8200h)
(EIDR2; 8208h)
(EIDR2; 8208h)
(EIDR4; 8210h)
(EIDR6; 8218h)
Access Mode: Read/Write, Global
The procesor views these registers as a set of 32-bit registers which are used to write or read data from
locations in the E-RAM devices attached to the PM2329.
Recall that each PM2329 device has a 32-bit E-RAM control bus and a 32-bit E-RAM data bus. Further,
the E-RAM control bus from all devices is connected to a shared memory device, and the E-RAM data bus
from each device is connected to a separate memory device. To access all these memory devices over the
E-RAM bus, there are essentially two E-RAM access registers implemented in the PM2329--one that can
access the memory connected to the control bus and the other that can access the memory connected to the
data bus.
These two E-RAM access registers are mapped to the C-Word bus and D-Word bus of the PM2329 cascade
depending on the CID# of the PM2329 as shown in below.
PM2329 0
C-Word Bus
PM2329 0
D-Word 0 Bus
PM2329 1
D-Word 1 Bus
PM2329 2
D-Word 2 Bus
PM2329 3
D-Word 3 Bus
PM2329 4
D-Word 4 Bus
PM2329 5
D-Word 5 Bus
PM2329 6
D-Word 6 Bus
PM2329 7
No D-Word Bus supported
Note that both the C-Word and the D-Word 0 buses are accessed using CID#0 and no D-Word is supported
on CID#7. In other words, both the E-RAM access registers in the PM2329 with CID#0 are used, only one
of the two E-RAM access registers in CIDs #1 through #6 are used and neither of the E-RAM access
registers in CID#7 are used.
This register set contains as many 32-bit registers as the physical width of the connected E-RAM. Based on
the Read/Write Data Enable in the E-RAM Indirect Address Register, the cascaded PM2329 devices can
read from or write to multiple 32-bit E-RAM words in a single cycle.
The E-RAM Configuration Register defines how the E-RAM is configured. Based on the configuration,
the E-RAM contains a C-Word (mandatory) and a set of (optional) D-Words.
Since these registers are distributed across the cascaded PM2329 devices, their validity depends on the
number of PM2329 devices in the cascade. Shown below is the association of these registers with the CID#
of the PM2329 devices: