[SOLVED] Pic18f4550 datasheet help?

Hello
I'm new beginning in Pic (microchip) so please explain it with sympathetic words.

well, but I was reading the datasheet pic18f4550 and read the memory:
"PIC18 microcontrollers implement a 21-bit program
counter Which Is Capable of addressing a 2-Mbyte
program memory space. Accessing a location between
the upper boundary of the physically implemented
memory and the 2-Mbyte address will return all '0 's (a
NOP instruction). "

but what do they think with 2 Mbyte can see that Micro processor is only 256 bytes EEPROM.

Hi,

First off, perhaps the 4550 USB chip is not the easiest one to start with.
USB is not a beginners project and it needs C anyway.
Perhaps look at something like the 4520 which is virtually the same but less the complications of USB.

The chips contain 3 types of memory - the main one being the On Chip (Flash) Program Memory, second the RAM for User and System Data and third the EEPROM which is used to store Users data when power is off.

The addressing method, in this case 21 bits, allows addressing up to 2 mb, so any future chips with larger Program Memory can be direclty addressed.
The 4550 chip just has 32k of Flash Program Memory for your program code.
If when writing your code you inadvertently address a location above its physical address of 32K then the resultant instruction will just return 00 - in other words it will just ingnore the incorrect instuction address.

thanks for your advise

Hi,

You are welcome - been on a year out trip ??