Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
Announcements

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. If you'd prefer to explore, try our test area to get started. And see here for current known issues.

New Member

Cisco router Configuration register

Hi all,

I was recently looking for some document on the Cisco configuration register values. After some reading I came to know its a 16-bit number.

Then I read this document:

http://www.cisco.com/en/US/products/hw/routers/ps133/products_tech_note09186a008022493f.shtml

The table lists several values for different bit positions & their meaning but I noticed one peculiar thing!

It says if the 6th bit is set then corresponding hex value is 0x0040 meaning ignore NVRAM contents

But if you convert 0x0040 to binary it will be 0000 0000 0100 0000 its the 7th bit that is set for this hex value not 6th as listed in the document. Similarly all the entries in the table given in document counts one bit less than actual value.

Anybody can advise why this is so?

Thanks a lot in advance

Everyone's tags (4)
1 ACCEPTED SOLUTION

Accepted Solutions
Hall of Fame Super Silver

Cisco router Configuration register

Hello Pradeep,

bit numbering in the table is 0 to 15. First index is 0 not 1, so bit 6 is actually the seventh bit from right to left using this indexing convention.

Hope to help

Giuseppe

2 REPLIES
Hall of Fame Super Silver

Cisco router Configuration register

Hello Pradeep,

bit numbering in the table is 0 to 15. First index is 0 not 1, so bit 6 is actually the seventh bit from right to left using this indexing convention.

Hope to help

Giuseppe

New Member

Cisco router Configuration register

oh!

Thanks a lot Giuseppe!!

I now realise it was my silly mistake to have missed noticing it.

543
Views
0
Helpful
2
Replies