code explaination

thank you Dan....i have written this to try and incriment the address:

        unsigned int address;
        unsigned char Packet;

for (address=0x00;address<0xff;address++)
                    {
                EEWrite(address,Packet);
                }

is this any good?

"is this any good?"

That will write the value contained in Packet to the first 255 EEPROM locations. If that is the desired outcome, then it's good.

no what i would like to do is receive a packet, which is a byte, write it to the first eeprom location then incriment that address for the next byte(packet)received then write that to the new address. how would i .do that...?

thanks you for ur knowledge

Then I guess you meant for Packet to be an array to hold the received packet, so something like (if packets are fixed in size):

#define PACKET_SIZE 256 /* or whatever */
unsigned int address;
unsigned char Packet[PACKET_SIZE];

for (address=0x00;address<sizeof Packet;address++)
{
    EEWrite(address,Packet[address]);
}

hi i have tried that and am getting this error:

TRANSMISSION.C(146): error C249: 'DATA': SEGMENT TOO LARGE

this dissapears when i comment out unsigned char Packet[PACKET_SIZE] any ideas?

"any ideas?"

Yes, you are probably using verbatim the code that provided only as an example without adjusting or rewriting it to suit your needs. You need to write code to suit your requirements, memory model, available memory, etc.

ok, now its getting complicated! im using a 25xx320 32k external eeprom, there is 4k on chip. how do i change these settings?

"TRANSMISSION.C(146): error C249: 'DATA': SEGMENT TOO LARGE

this dissapears when i comment out unsigned char Packet[PACKET_SIZE] any ideas?"

The message says that the DATA segment is too large.
What do you think might be the maximum size for the DATA segment...?

Are you familiar with the 8051's DATA, IDATA, XDATA, etc memory areas?

How big do you think unsigned char Packet[PACKET_SIZE] is going to be?
Will it fit into DATA...?

If it doesn't, what could you do?

"now its getting complicated!"

Not really, you simply select the C51 memory model to match the capabilities of your target device along with how you have designed and written your code. Your particular needs for packet byte buffering may very well fit in the 8051's DATA space.

You control the memory model settings using the GUI and/or command line and/or pragma (all means are explained in the toolchain guides and manuals), but in any case, the memory model has no bearing on the external EEPROM since that (presumably) uses a serial interface.

no i have not come across data segments before. i have did a little research and have changed output options to LARGE:Variables in XDATA.......and i have raised the PACKET_SIZE to 3000...enough to store approx 3 hours of data. The error has now gone....problem solved???

no i have not come across data segments before.
If you want success, you need to get more familiar with the processor and the tools before forging on.

have changed output options to LARGE:Variables in XDATA.......and i have raised the PACKET_SIZE to 3000...enough to store approx 3 hours of data. The error has now gone....problem solved???

sure, but the right way? at the same time, you have, probably slowed the execution speed by 2 times or more.

Revert to SMALL and uniquely qualify your array to xdata.

Using LARGE can cost execution penalties of great magnitude and, typically will increase your code size by a large amount.

Code a for loop moving something to your array and look at the generated assembler for SMALL and LARGE

Erik