Hi,
Oleg Sergeev wrote:

>First of all, it seems you mixed Flash Drivers API with USB Bootloader API.

I was always talking of the Flash API. It is just explained in Atmel's documentation concerning the USB Bootloader (doc4287.pdf from www.atmel.com) on pages 24ff.
The API differs much from other Atmel AT89C51xxxx devices (as far as I can see from the documentations).
Passing parameters in the memory addresses 0x1C .. 0x1F is explicitly mentioned there.

> For example, to read
> Manufacturer ID (__api_rd_manufacturer) you should do something like:
> ; save interrupts and registers; clear EA
> ; ....
> MOV R1,#0x00 ; command: read IDs
> MOV DPTR,#0x0000 ; descriptor: ID of Manufacturer
> ; map bootloader and reset watchdog if used
> ; ....
> LCALL 0xFFF0 ; invoke Flash API

I had tested this register-type parameter passing already BEFORE posting my question, with the same results. As it doesn't match with the docs I didn't think of talking about that in my previous posting.

Kind regards,

Bernhard Müller
EDB Systeme Wien