Programing Xflash while running from protected I-Flash

[rana]

Posted on May 07, 2007 at 07:18

Programing Xflash while running from protected I-Flash

[rana]

Posted on May 07, 2007 at 05:47

Hello all.

I was wonder whether can I program Xflash while running from protected I-Flash.

Thanks.

Ran

[najoua]

Posted on May 07, 2007 at 06:51

Hello Ran,

It is possible to write the X-Flash while fetching from protected I-Flash.

For more details, please refer to the ST10F276 datasheet, section 4.5.9 Access protection, Table 26, page 40/229.

According to the table, when I-Flash is access protected, ''Read XFLASH/Jump to XFLASH and write Flash registers'' operations are allowed.

Best regards,

Najoua.

[rana]

Posted on May 07, 2007 at 07:02

Thanks.

Second Q:

Can I run from Xflash and program It?

(probably no, but what can lose?)

Ran

[najoua]

Posted on May 07, 2007 at 07:18

Hi again Ran,

The Flash 4 Banks (Bank0&1 in I-Flash and Banks 2&3 in X-Flash) have their own dedicated sense amplifiers, so that any Bank can be read while any other Bank is written.

You can program Bank3 when fetching from Bank2 and conversely.

During a Flash write operation, any attempt to read the bank under modification will output invalid data (software trap 009Bh). This means that the Flash Bank is not fetchable when a write operation is active.

Best regards,

Najoua.