
PM5317 SPECTRA-9953 Telecom Standard Product Data Sheet
Release
Proprietary and Confidential to PMC-Sierra, Inc., and for its customers’ internal use.
Document No.: PMC-2000741, Issue 5
131
15 Normal Mode Register Description
Normal mode registers are used to configure and monitor the operation of the SPECTRA-9953
device. Normal mode registers (as opposed to test mode registers) are selected when TRS
(A[14]) is low.
Notes on Normal Mode Register Bits:
1. Writing values into unused register bits has no effect. However, to ensure software
compatibility with future, feature-enhanced versions of this product, unused register bits
must be written with logic 0. Reading back unused bits can produce either a logic 1 or a
logic 0; hence, unused register bits should be masked off by software when read.
2. All configuration bits that can be written into can also be read back. This allows the
processor controlling the SPECTRA-9953 device to determine the programming state of the
device.
3. Writeable normal mode register bits are cleared to logic 0 upon reset unless otherwise
noted.
4. Writing into read-only normal mode register bit locations does not affect SPECTRA-9953
operation unless otherwise noted.
5. Certain register bits are reserved. These bits are associated with megacell functions that are
unused in this application. To ensure that the SPECTRA-9953 device operates as intended,
reserved register bits must only be written with the logic level as specified. Writing to
reserved registers should be avoided.