array with pdata

i got an error code "error C241: 'main': auto segment too large"

That's not nearly sufficient info. You have to show an actual, complete example case that exhibits the problem. You haven't even told us whether that variable has static or automatic storage duration!

Furthermore this

unsigned char pdata array_1[8][16];
unsigned char data *p1;
p1 = &array_1[0][0];

makes no sense whatsoever. How do you expect a memory-class specific pointer (p1 points to data) to be able to point at data of a different memory class (pdata)?

i got an error code "error C241: 'main': auto segment too large"

That's not nearly sufficient info. You have to show an actual, complete example case that exhibits the problem. You haven't even told us whether that variable has static or automatic storage duration!

Furthermore this

unsigned char pdata array_1[8][16];
unsigned char data *p1;
p1 = &array_1[0][0];

makes no sense whatsoever. How do you expect a memory-class specific pointer (p1 points to data) to be able to point at data of a different memory class (pdata)?

excuse me for my ignorance but how can i tell if a variable has static or automatic storage duration.
i dont expect nothing, what wrong with the pointer , please advice me what to do.

an ex

normally, if you see the specifier "static" along with the definition of a variable, it is static, like this:

static int x ;

whether you make the variable static in a function or file scope is your business.
But if the "static" keyword is missing and the variable is in function scope, it is an automatic.

This is standard terminology of the 'C' programming language - so the place to look is a 'C' textbook.

I'm very familiar with the 'C' textbook.
that wasn't the issue , i found the problem eventually.
first of all i'll describe the issue:
i need to use a dynamic 3D array: (global of course)

unsigned char disp[15][25];

Only the array takes about 375 Byte's, i think, and if i'm wrong i'll be very happy, which is definitely way over my primitive hardware limitation,
So, do i have to use a flash memory along with my current EPROM M27C256B to populate the program variable's and surely the large array i'm using.
and if so any suggestion please ?

What is dynamic about this variable?

unsigned char disp[15][25];

Get a chip with a lot of RAM, or check if your algorithm needs this amount.

80c31 where did you find that anachronism?

how much XDATA (external RAM) do you have?

Erik

My project is a dot matrix display 16(rows)x192(bit's wide) (8x8 dot), and i need this array for shifting the bits all together in a loop.
i don't have any XDATA at all.
does external RAM is necessary for this kind of job ?
or can you recommend another uC with 40DIP socket to hold this amount of data ?

Only the array takes about 375 Byte's, ... i don't have any XDATA at all.
so where do you propose to put the 375 bytes, can you put them in codespace i.e. will they ever change?

can you recommend another uC with 40DIP socket to hold this amount of data

find it in "the Keil device database"

http://www.keil.com/dd/parm_search.asp

Erik

unsigned char disp[15][25];

That is neither dynamic nor 3D!

And why global "of course" ?

you right. 2D.
it needs to be global type variable.
still not enough room.

You didn't answer the question: can it go into CODE space?

If not, you'll just have to provide more RAM - either a different chip with (more) internal RAM, or add external RAM.

i'm sorry i didn't see the question.

it can go into CODE space only if i can modify the values there (by tricks or something), if not then i'm guessing external RAM is the only way.

i thank you very much for your help forum.
still i have much to learn...

CODE space is read-only

"if not then i'm guessing external RAM is the only way"

Unless you get a processor with sufficient internal RAM...

Start with the so-called "bible" for the 8051:

Chapter 1 - 80C51 Family Architecture:
www.nxp.com/.../80C51_FAM_ARCH_1.pdf

Chapter 2 - 80C51 Family Programmer's Guide and Instruction Set:
www.nxp.com/.../80C51_FAM_PROG_GUIDE_1.pdf

Chapter 3 - 80C51 Family Hardware Description:
www.nxp.com/.../80C51_FAM_HARDWARE_1.pdf

Here are some other introductory & reference materials:
http://www.keil.com/books/8051books.asp
www.8052.com/books.phtml
www.8052.com/tutorial.phtml

You will need to read the Data Sheet for your particular processor