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Locating 2 parameters at the same address

Jeff Tonkinson

I am using an 8051 (C51/BL51) with no off-chip memory. I have two functions with parameters:

void Detect( U8 iLed )

and

static U8 INHSampleHandler( U16 u16Sample )


Now I understand that Keil will allocate a variable (in DATA) for these. The problem seems to be that the locator is using the same memory location for both. I cannot understand why.

Below are excerpts from the scratchpad showing 2 "D:0026H". These are the only places these symbols are declared. Any ideas what I'm doing wrong?

Thanks,
Jeff

BL51 BANKED LINKER/LOCATER V5.12              07/14/2011  09:36:23  PAGE 1


BL51 BANKED LINKER/LOCATER V5.12, INVOKED BY:
Z:\TOOLS\SOFTWARE\KEIL\BL51.EXE Z:\Software\FB_CPU_Init.obj,
>> Z:\Software\Settings.obj, Z:\Software\Glo
>> bals.obj, Z:\Software\Devices\Clock.obj, Z:\ 
>> Software\Devices\Flash.obj, Z:\Software\Devices\HMI.obj
>> , Z:\Software\Devices\INH.obj, Z:\ 
>> Software\Devices\ADC.obj, Z:\Software\Devices\Timer.obj, Z
>> :\Software\Builds\TestINH - 06-00039-21-09\Main.obj
>> , Z:\Software\Test\Test_Button.obj, Z:\So
>> ftware\Builds\TestINH - 06-00039-21-09\Version.obj TO Z:\ 
>> Software\Builds\TestINH - 06-00039-21-09\06-00039-21-09-xx.wsp
>>  RS (256) PL (68) PW (78) XDATA (?XD?SETTINGS (0X0)) CODE (?CO?VERSION (0X7
>> FC0))


MEMORY MODEL: SMALL

Deleted for brevity

  -------         PROC          _INHSAMPLEHANDLER
  D:0026H         SYMBOL        u16Sample
  C:0BF1H         LINE#         150
  C:0BF5H         LINE#         151
  C:0BF5H         LINE#         207
  C:0BF7H         LINE#         208
  -------         ENDPROC       _INHSAMPLEHANDLER
  -------         ENDMOD        INH

Deleted for brevity

  C:09FEH         PUBLIC        _Detect
  C:074EH         PUBLIC        main
  -------         PROC          _DETECT
  D:0026H         SYMBOL        iLed

Parents
  • 0 in reply to Andy Neil

    this is exactly what IB wrote:

    'There's NO problem with calling a function from an '51 ISR.

    However, like most tasks, the programmer needs to understand the mechanism(s) involved and take appropriate steps to ensure the cogs fit correctly.

    FWIW, we have plenty of code that calls functions from ISRs. It's all written in assembler and there have been no reported problems. Quite a few of those functions are inherently re-entrant. They are called from both ISR and mainline code. Most importantly, parameters and local variables are passed in registers.

    No problem, so long as you know what you're doing, period.'

    vs. what you characterized what he wrote:

    "There are NO problems"

    come on. would any reasonably intelligent people equate the two?

    as I stated before, the two of you said the same thing, with different emphasis. and there is no point in pushing any of your statements to the extreme to justify the other.

Reply
  • 0 in reply to Andy Neil

    this is exactly what IB wrote:

    'There's NO problem with calling a function from an '51 ISR.

    However, like most tasks, the programmer needs to understand the mechanism(s) involved and take appropriate steps to ensure the cogs fit correctly.

    FWIW, we have plenty of code that calls functions from ISRs. It's all written in assembler and there have been no reported problems. Quite a few of those functions are inherently re-entrant. They are called from both ISR and mainline code. Most importantly, parameters and local variables are passed in registers.

    No problem, so long as you know what you're doing, period.'

    vs. what you characterized what he wrote:

    "There are NO problems"

    come on. would any reasonably intelligent people equate the two?

    as I stated before, the two of you said the same thing, with different emphasis. and there is no point in pushing any of your statements to the extreme to justify the other.

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