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ST7FLITE39 - how to use internal clock for correct load of bootloader?

djbrano
Associate II
Posted on September 09, 2009 at 06:29

ST7FLITE39 - how to use internal clock for correct load of bootloader?

2 REPLIES 2
djbrano
Associate II
Posted on September 09, 2009 at 06:29

Hi all,

I am new in this forum and I try to find solution for my problem.

I try to make support of ISP programming for ST7 devices.

I have already done it, but just one problem still appears.

Everything is fine only when I use external clock on PB4/CLKIN pin.

(flash programming, reading, etc.)

As I read device datasheet:

''In remote ISP mode, the ST7 has to be supplied with power (VDD and VSS) and an internal or external clock signal (you can use any of the oscillator configurations described in the datasheet)''

Now here is my problem with a clock signal. When I use external clock

on PB4/CLK IN pin (generating 35 pulses on ICCDATA pin), as I said - I have no problem with device programming.

When I use internal clock, (generating 38 pulses on ICCDATA pin

instead of 35) device can not load bootloader correctly and sometimes

bootloader is not loaded completely.

How to enable internal clock correctly or where is the problem for

correct load of a bootloader?

Thank you

mighel84
Associate II
Posted on April 16, 2010 at 12:48

If you use internal clock instead of external clock check Option Byte[0,1]... If it is wrong the uC become strange.

Try if it work... 🙂