FCS, failure to step

[Matt1of3]

Hi All

I have 2 questions, I'm using Codewarrior 10.0, mcs08ac16 controller

1)      The PEmicro drop down menu on the tool bar is turned off, how do I turn it on?

2)      I’m having difficulty with the Full Chip Simulator when using the BCLR instruction.  If I try to set a bit in RAM (first page) it will not work, I get a “Target request failed: Failed to step" error.  I also have problems with the Assembler at the same instruction:

BCLR  1,$71  will assemble but will not step

BCLR  1,0x71 will not assemble, I get and “End of line expected “ error A2400

BCLR  1,113            will assemble but will not step.

When I’m using the BDM the code will run although I get a warning on the BCLR Instructions.  If it Assembles the disassembly looks good to me.

Is there a way I can get the simulator to accept bit instructions to low RAM?

Thanks and regards,

[bigmac]

Hello,

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Matt1of3 wrote:

2)      I’m having difficulty with the Full Chip Simulator when using the BCLR instruction.  If I try to set a bit in RAM (first page) it will not work, I get a “Target request failed: Failed to step" error.  I also have problems with the Assembler at the same instruction:

BCLR  1,$71  will assemble but will not step

BCLR  1,0x71 will not assemble, I get and “End of line expected “ error A2400

BCLR  1,113            will assemble but will not step.

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I assume that you have a .asm file, and you are not using HLI assembler within a .c file.  For a .asm file, the representation of a hexadecimal number uses the $ prefix only.

The FCS objects to reading "uninitialised" memory locations, even though the MCU itself would actually return the value containing the "garbage" bits.  The BCLR instruction is actually a read-modify-write type, where the whole byte value is read.  If this be the issue, simply initialise the memory location with MOV #0,$71 during the POR initialisation process to ensure that all bits are initialised.

Regards,

Mac

[Matt1of3 · Accepted solution]

Thank Mac, Spot On!   We usually initialize flags with the bit instructions, I wouldn’t have figured this out.