B-5
Cisco 7204 Installation and Configuration Guide
OL-5101-02
A P P E N D I X
B
Configuration Register Information
The following information is found in this appendix:
•
Configuration Bit Meanings, page B-5
•
Displaying the Configuration Register While Running Cisco IOS, page B-9
•
Displaying the Configuration Register While Running ROM Monitor, page B-9
•
Setting the Configuration Register While Running Cisco IOS, page B-10
•
Setting the Configuration Register While Running ROM Monitor, page B-10
Configuration Bit Meanings
Use the processor configuration register information contained in this appendix to do the following:
•
Set and display the configuration register value
•
Force the system into the bootstrap program
•
Select a boot source and default boot filename
•
Enable or disable the Break function
•
Control broadcast addresses
•
Set the console terminal baud rate
•
Load operating software from ROM
•
Enable booting from a Trivial File Transfer Protocol (TFTP) server
Table B-1
lists the meaning of each of the configuration memory bits. Following the table is a more
in-depth description of each setting.
Table B-1
Configuration Register Bit Settings
Bit No.
Hex
Meaning
00–03
0x0000–0x000F
Boot field
06
0x0040
Causes the system software to ignore nonvolatile random-access
memory (NVRAM) contents
07
0x0080
OEM (original equipment manufacturer) bit enabled
08
0x0100
Break disabled
10
0x0400
IP broadcast with all zeros