USB Free Memory

[richard.c]

Hi All,

Just wanted to know, if someone would be good enough to tell me, roughly how much free program memory space is left on a chip like the pic18F4550 after it is programmed with all the coding for a USB to PC link ?

My other consideration is the chip needs to be a DIL package

Trying to work out if its better to do it all, usb and my program code proper in one chip, or to fit an extra little board like a UBW.

thanks

Richard

 

[Hero999]

What are you asking?

The amound of disk space after it's been formated depends on the file-system, i.e. whether it's formatted with FAT32, ntfs or ext3.

 

[picasm]

What are you asking?
.

Hero999 I think you misunderstood the question.
I think he wants to know how much memory is used by the Microchip usb stack in a pic 18f4550.

It uses about 2-4 Kb depending on what usb options are needed (eg. 2k for a minimal usb bootloader or 3K for HID class firmware.)
see:
**broken link removed**

Should leave plenty of space for your own program on a 18f4450 which has 32K total available ( 16K of actual instructions)