Our product was losing flash, too. I took Georg Bende's advice, and
we've never seen the problem again:
1) You should always erase the flash before programming; but this isn't an
issue most of the times, because when the flash content is verified, it is
written in it.
2) We have had a similar problem: some drives lost part of their content when
powered off abruptly. The solution came from Mr. Daniel Malik:
(...)
"The only thing I can possibly think of which might affect you is section 16.4
of the manual - high speed operation is not guaranteed below power supply
voltage of 2.7V. I believe you should implement the low voltage interrupt to
disable PLL in case of power failure and wait in an infinite loop for POR
circuit to reset the part as the voltage drops even further. The COP circuit
should be enabled to reset the part in case the power failure is momentary and
the power supply recovers before the POR kicks in."
(...)
That's exactly we did; the low-voltage interrupt switched over to 8 MHz
operation, enabled the watchdog, and kept the code in the interrupt handling
routine until the low voltage interrupts were cleared. This actually solved all
the flash losses.
Georg Bende
----- Original Message -----
From: Charlie W
To: Ching CheeWee ; m...
Sent: Friday, April 07, 2006 7:13 PM
Subject: Re: [motoroladsp] Program flash problem for 56F8366
microcontroller
I saw the same problem beform. After I shorted JTAG
parallel cable and ture the flash verification on. The
problem was gone.
--- Ching CheeWee wrote:
> Hi all,
>
> I have a firmware that blink an LED light on
> the board to indicate that the firmware is operating
> properly. The firmware works properly until recently
> upon power up, the LED light did not blink.This
> occurs despite repeated power on and power off of
> the board. I suspected that the program flash has
> being erased. This is because upon reprogramming of
> the firmware, the LED light blinks again. The LED
> light continues to work with repeated power on and
> power off of the board. I hope that somebody can
> enlighten me on this issue. Thank you very much.
>
> Regards,
> Chee Wee
>
>
>
>