Data Types

[migsantiago]

Hello!

I was wondering which the limits were for a variable depending on its type. I looked in CCS help but I only found this:

int1
Defines a 1 bit number
int8
Defines an 8 bit number
int16
Defines a 16 bit number
int32
Defines a 32 bit number
char
Defines a 8 bit character
float
Defines a 32 bit floating point number
short
By default the same as int1
Int
By default the same as int8
long
By default the same as int16
void
Indicates no specific type

I was looking for the range that these types have; for example, int8 goes from 0 to 255.

I was told to read the file float.h but I only got some facts and I got confused

Please tell me where to find a table that includes this info.

Thanks in advance!

[Ttelmah]

Use a calculator.
The size of number that an integer format can hold, is 2^n, where 'n' is the number of bits used to hold the value. So an int16, can hold 2^16 = 65536 values. You have to include '0', so the values can be 0 to 65535.
For 'signed' numbers, one bit is used to hold the sign, so a 'signed int8', can only hold 2^7 positive values.
The definition you give for 'void', is the one for C++ (where a void can be used to return any numeric type, and then converted to the required form). In CCS C, void specifically means 'no return'.
In a 'float', you have what is effectively a 24bit integer (only 23 bits are actually stored), which is then scaled by the exponent. The values in float.h, give the ranges for this. Basically you get slightly over 6 decimal digits of accuracy, scaled to cover numbers from 'FLT_MIN', up to 'FLT_MAX'.

Best Wishes

[dyeatman]

If you are unable to count in binary you may be in for some serious problems trying to write programs...but here goes...

Basically the number of bits tells you the range:

8 bits allows you to count in binary 0-255
16 bits = 65535
32 bits - 4,294,967,295

This is for unsigned vars.

For signed variables the range is 1/2 the above and the MSB (most significant bit) is used as the sign bit to allow +/-.

Example: SIGNED 16 bit vars can hold from +32,767 down to -32,768

Here is a link to explain the ANSI C data types/byte sizes:
http://www.phim.unibe.ch/comp_doc/c_manual/C/CONCEPT/data_types.html

Keep in mind the CCS variable sizes are different than standard ANSI C as you listed earlier so you have to translate (e.g. INT in CCS is 8 bits but is 16 bits in ANSI C).

Good Luck!

EDIT: Sorry TTelmah, it seems I came I right after you did...

[migsantiago]

Thank you guys, I also had some questions about the signs (+/-) but now they're solved.