how to use int16

[nbt1987]

I use CCS, PIC8F4431. I declare int16 variable as follow:

[PCM programmer]

The CCS manual says this, on page 44 (page 56 in the Acrobat reader):

[Rohit de Sa]

The first problem I see in your code is 'tong' is not a byte, its is a word.

I gather from your code snippet that you want to access the high and low byte of 'tong'. Try this:

[Rohit de Sa]

Hmm, was just checking out #byte and #word.
This is my code:

[Ttelmah]

#byte, creates a 'byte' variable at an address _or_ if given the name of an existing variable, locates that variable 'at' the address.
#word, creates a 'word' variable, or again if given the name of an existing variable, locates that variable 'at' an address.

So, in the case of 'tong', it is perfectly OK, to declare an int16, and use #byte to locate it, or to just use:

#word tong=0x58

Rohit. ptr, is a pointer to an int16 value. It doesn't care whether the value has been declared earlier to be an 8bit value, or a 16bit value.

The original code posted by nbt1987, is OK, _except_ that the order of the bytes is reversed.

Best Wishes

[bkamen]

I usually use structs and unions to access multi-byte values. Maybe it's way easier on the eyes and a little more portable.

one variation might be:

struct {

int8 low;
int8 hi;

} val;


val.hi = 0xff;
val.lo = 0x44;
_________________
Dazed and confused? I don't think so. Just "plain lost" will do. :D

[Rohit de Sa]

Ttelmah, the reason I'm still confused is because the CCS help explicitly states that if the variable does not exist, then #byte creates an int8, and #word creates an int16. Did the manual mean 'locate' instead of 'create'?

Rohit

[nbt1987]

Thanks for all!
When i change the address as follow:

int16 tong;
#word tong = 0x201
#byte tongH = 0x202
#byte tongL = 0x201

It's true.

[bkamen]

I still don't understand why you are explicitly laying out a variable in memory when the compiler (is supposed to and) does it for you?

-Ben
_________________
Dazed and confused? I don't think so. Just "plain lost" will do. :D