STANDARD PRODUCT
PM4351 COMET
DATA SHEET
PMC-1970624
ISSUE 10
COMBINED E1/T1 TRANSCEIVER
Register 00DH: Revision/Chip ID/Global PMON Update
Bit
Type
Function
Default
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
R
R
R
R
R
R
R
R
TYPE[2]
TYPE[1]
TYPE[0]
ID[4]
0
0
1
0
0
1
0
1
ID[3]
ID[2]
ID[1]
ID[0]
The version identification bits, ID[4:0], are set to a fixed value representing the
version number of the COMET. For COMET Rev G, ID[5] was added to the
Master Diagnostics register (address 00AH).
In order to uniquely identify Rev G in software, the following routine can be
executed:
i. Read Register 00DH: Revision/Chip ID/Global PMON Update. Revision F or
Revision G will contain “00100101”.
ii. Read Register 00AH: Master Diagnostics. In Revision F, bit 6 will read logic
0, as this is the value charged on the bus-holder due to the last read. In
Revision G, bit 6 will read logic 1, as this is the value driven by the new ID[5]
bit.
NOTE: For this two step sequence to work, step (ii) must follow immediately after
step (i) without any intervening microprocessor accesses. Any intervening
accesses could change the value charged onto the bit 6 bus-holder, invalidating
step (ii).
Writing any value to this register causes all performance monitor counters to be
updated simultaneously.
The chip identification bits, TYPE[2:0], are set to “001” representing the COMET.
PROPRIETARY AND CONFIDENTIAL
103
PMC [ PMC-SIERRA, INC ]
