MPLAB help

[Electronics4you]

I need to know what this means:

variables	UDATA 0x30
ptr_pos		RES 1

 

[Pommie]

It's a uninitialised data area. It's uses to write relocatable code. Assuming your a beginner, it's better to write absolute code to start with.

Mike.

 

[mramos1]

I think it means you have (allocate) 30 (hex) bytes of RAM to work with offset from variables.

 

[Pommie]

I think it means you have (allocate) 30 (hex) bytes of RAM to work with offset from variables.

Not quite right, it means the variable area will be placed at 0x30 and 1 byte will be reserved for ptr_pos at 0x30.

Mike.

 

[Electronics4you]

What about the next line in the code

variables	UDATA 0x30
ptr_pos		RES 1
ptr_pos2	RES 1

is this also placed on address 0x30 with 1 byte reserved?
Can I write like that:

ptr_pos2	RES 2

to reserve 2 byte for the constant?
Where can I in addition find information about things like RES, UDATA, $-3 and other things concerning asm PIC programming?

 

[Nigel Goodwin]

Where can I in addition find information about things like RES, UDATA, $-3 and other things concerning asm PIC programming?

In the helpfile!.

 

[mramos1]

Sorry, Pommie is right.

UDATA 0x30 UserDATA start at location 30 hex in memory.
ptr_pos1 is a symbol to reference a location.
RES ? is reserve ? number of byte(s) at the reference location.

 

[sheng_james]

where can i download math lab installer???pls help me i search already in the net but i found no one. it is usefull in our data communication subjects..