topic Flash Block Protection / Vector Redirection in 8-bit Microcontrollers

Flash Block Protection / Vector Redirection

gueggi — Mon, 06 Nov 2006 23:08:00 GMT

Hi,

i will used the 'FLASH Block Protection' and 'Vector Redirection' functionality of the MC9S08GB60A controller.

Questions:

- It is possible with this configuration to re-program the protected area?

- Is the 'Vector Redirection' available without 'Flash Block Protection'?

Thanks for your help.

Regards ...

Re: Flash Block Protection / Vector Redirection

Alban — Tue, 07 Nov 2006 00:15:00 GMT

Hello !

Q1- It is possible with this configuration to re-program the protected area?

A1- Only after a mass-erase and un-secure of the Flash.

Cheers,

Alban.

Message Edited by Alban on 2006-11-06 04:17 PM

Re: Flash Block Protection / Vector Redirection

Alban — Tue, 07 Nov 2006 00:19:49 GMT

Hi Again,

Q2- Is the 'Vector Redirection' available without 'Flash Block Protection'?

A2- in datasheet, answer is no.

Whenever any block protection is enabled, the reset and interrupt vectors will be protected. Vector redirection allows users to modify interrupt vector information without unprotecting bootloader and reset vector space. Vector redirection is enabled by programming the FNORED bit in the NVOPT register located at address $FFBF to zero. For redirection to occur, at least some portion but not all of the FLASH memory must be block protected by programming the NVPROT register located at address $FFBD. All of the interrupt vectors (memory locations $FFC0–$FFFD) are redirected, while the reset vector ($FFFE:FFFF) is not.

Alban.