Why can not boot from internal memory?

[xakaicheng]

Posted on February 12, 2007 at 10:48

Why can not boot from internal memory?

[xakaicheng]

Posted on February 09, 2007 at 03:35

I'm using STR710FZ2T6

when i boot from external RAM(BOOT0=1, BOOT1=1), it's ok.

when i boot from internal FLASH or RAM(BOOT0=0, BOOT1=1/0) with a reset signal, it can not run, but if I turn on the power, it can run, Why?

By the way, the reset signal is generated by MAX806, it has no problem.

Thanks!

[tech9]

Posted on February 09, 2007 at 13:23

Hi Fisherman,

Try it with BOOTEN =0, see how it behaves then.

Also, according to your clock specs, check that you do not exceed the speed when running from flash...

Regards,

Tech / Jp

[xakaicheng]

Posted on February 09, 2007 at 15:58

hi Tech,

Thank you for your answer.

the clock is 32MHz.

If BOOTEN =0, it can boot from Internal Flash with a reset signal.

So, why I can not boot from Internal RAM?

Thanks.

[tech9]

Posted on February 09, 2007 at 18:15

See page 22 and 23 of manual revision 7.

''In the STR71x, three boot modes are available and can be enabled by means of three input pins: BOOTEN, BOOT0 and BOOT1.

BOOTEN is a dedicated pin. It must normally be tied to ground through a 10K resistor. When BOOTEN = 0, the device is in FLASH boot mode, the BOOT[1:0] pins are not used, and they may have any value.

When BOOTEN = 1, the BOOT[1:0] pins are latched at the second CK rising edge after the release of the external RSTINn pin. Their value is used to configure the device BOOT mode.''

So if you put BOOTEN =0; you'll never be able to boot from RAM again...

You would have to use your previous configuration.

Hope this helps!

Tech / Jp

[xakaicheng]

Posted on February 10, 2007 at 00:36

hi Tech,

I know when BOOTEN=0, it can boot from FLASH only.

What I want to know is why when BOOTEN=1, BOOT0=0, BOOT1=0 or 1, it can't boot from FLASH or RAM by a Reset signal, but can boot by turn off/on power.

Is there any difference between signal Reset & power on Reset?

Thanks a lot.

[tech9]

Posted on February 12, 2007 at 10:48

Hi Fisherman,

Maybe there is something wrong with the timing of the reset signal, the oscillator and the other stuff connected to your MCU?

Could you check that your reset signal sequencing respects the diagram in the manual (figure 7), that is the only hint I can give you here. I have never experienced a difference between power on reset and /reset on our board.

Good luck with your development, hope you solve your issue soon enough!

Tech