How big file could be uploaded IAP

yahoo1 · ‎2006-10-25

Posted on October 25, 2006 at 11:47

yahoo1 · ‎2006-10-24

Posted on October 25, 2006 at 08:45

Dear All,

How big could be size of program uploaded via IAP. I saw in the PDF that it is sored in the RAM, so is it limited to size of RAM or the size could eb 256 KBYTES.

THank you for your help

Kind regards

richards2 · ‎2006-10-25

Posted on October 25, 2006 at 11:28

You need a loader program to do the IAP. You need to run the IAP/loader software from RAM while you are programming the flash or from the bank of flash you are not programming. You can write the loader to accept packets of data over your preferred external interface (eg: USB or UART) and then program the entire 256K piece by piece.

The obvious issues are:

- the security to authorise the programming operation, if that is a concern

- what happens if there is a power failure or other unexpected failure during the reprogramming of the flash assuming that the JTAG is disabled for security reasons. (boot block of the flash in particular)

Our application is less than 128K and we have opted to go the route where the first 128K contains a USB loader and selftest application. The second 128K contains the user mode application. We do not plan to reprogram the first 128K unless there is a major bug. The second 128K can be reprogrammed via a secure download process via USB.

richards2 · ‎2006-10-25

Posted on October 25, 2006 at 11:47

you could also try the ''USB Developer Kit for STR7 - Beta1 Posted'' posted to this forum. Either search for that topic of try the following link.

http://mcu.st.com/mcu/modules.php?mop=modload&name=Splatt_Forums&file=viewtopic&topic=4264&forum=17

There is a USB firmware download sample that has a memory footprint of 6K to 8.5K depending on the compiler you use. I have not tried it myself, but others report success.