JM60 USB Bootloader

[thrillseeker]

Hi All,

        i'm currently having a project using mc9s08jm60 and i'm interested in using the usb bootloader capability. i've already read the AN3561pdf. Just want to ask some questions regarding the AN3561SW. First, I was wondering why the value in the Flash Protection Register is 0xFA and not 0xFB. it was stated that the Bootloader code starts at 0xFC00. Isn't it that the address before 0xFC00 is 0xFB and not 0xFA?Second is, how would I determine the start and end address if I will redirect the vector table?Will I have the liberty to change this myself or is the redirection of vector table permanently 0xFBC0-0xFBFD?Lastly, what does the address of 0xFABC mean in the UserEntry Function? I have so many questions because the pdf didn't explain these things.Thanks for your reply!

Regards,

thrillseeker

[DerekLau]

The first bit of the FPROT is Flash Protection Disable. There are only seven bits of Flash Protect Select Bits in the FPROT. Set FPROT to $FA is correct which means the last unprotected address is $FBFF.  The redirection vector table depends on the value of FPORT. When FPROT = $FA, redirection vector is 0xFBC0-0xFBFD. When FPROT = $F8, redirection vector is 0xF9C0-0xF9FD. The address of 0xFABC in the UserEntry Function means the UserEntry program is put at $0xFABC. However I think you can just remove this.

Message Edited by dereklau on 2008-11-06 02:12 PM