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MON166: Monitor Warning, CODE_START is Equal to VECTAB

Information in this article applies to:

  • Keil Pk166 All Versions


I'm customizing MON166 to use the Simulated Serial I/O over my target board and the following parameters are being used in, the monitor configuration file:

; Definitions of Monitor Parameters
; ---------------------------------
; DATA_START: Defines the Start Address for the Monitor Data Area
;             Monitor uses 512 Bytes RAM starting at this location.

   %DEFINE ( DATA_START ) ( 17E000H )     ; default Monitor data area 0x17E000 .. 0x17EFFF

; CODE_START: Defines the Start Address for the Monitor Code Area
;             Monitor requires 6KB for program code starting at this location.

   %DEFINE ( CODE_START ) ( 000000H )

; VECTAB: Defines the Interrupt Vector Address relocation
; Notes: This setting is ONLY relevant, if CODE_START is 0.  Locate interrupts
;        in your target application to the same address with µVision
;        Project-Options for Target-L166 Misc-Interrupt Vector Table Address
;        (generates the L166 VECTAB directive).

   %DEFINE ( VECTAB ) ( 100000H )         ; Address 0x100000

The simulated serial I/O works fine. When I start target debugging, I receive the following Monitor Warning message:

Monitor Warning
   Monitor Configuration seems to be wrong!
   Please check the following item of your monitor configuration:
- Monitor code address ( CODE_START) is equal to the interrupt vector address relocation ( VECTAB )

When I look at my, I see that VECTAB and CODE_START are not equal.

If they are not equal, why is this message showing up?


It's a typical problem when the following lines of code are missing from the inst167.a66 monitor installation file:

RESET_ADR      EQU     %VECTAB      ; RESET IP value
RESET_ADR      EQU     0

If the above code is not in the inst167.a66 file, this warning message displays.


You may go to C166\MONITOR\ and look for inst167.a66 in any subfolder. This file contains that code.

You may also use C166\MONITOR\USER167 as a start point for your own C167 family monitor.


  • Getting Started and Creating Applications with µVision and 166/ST10 Microcontroller Development Tools in Chapter 11: Using Monitor-166


Last Reviewed: Thursday, February 25, 2021

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