Max. freq when using Indart-stx USB

[adib]

Posted on September 01, 2004 at 09:37

Max. freq when using Indart-stx USB

[adib]

Posted on September 01, 2004 at 06:26

Hi,

I am working with ST72F264 MCU and with Indart-STX USB debbuger.

The MCU is working with Fosc=16Mhz (Fcpu=8Mhz).

When I start debugging, the clock going into the STX (on pin #9) gets totally distorted. When I disconnect the Indart-STX the clock returns to normal.

I was wondering if the Indart debugger can work with 16Mhz?

[pete3]

Posted on September 01, 2004 at 07:59

Gilat,

The inDART sends its own clock to the board (12MHz?) throught the ICP line and this interferes with the clock on your board. You might have some luck putting a switch on the line to open/close this circuit but there are no guarantees this will work. You require this line to be connected to program the device. It's pin 9 of the connector.

With the 561 I have discovered that your option bytes are changed when using the debug mode. You will therefore have to reprogram the device (using DataBlaze or similar) if you want to use the chip without this option. Behaviour is unpredictable at best if you're using the wrong option bytes!

To find out the ''real'' frequency your chip is operating at I suggest you code a quick assembly routine to toggle a pin and measure this frequency. You can then work back and get the internal frequency of your device.

Incidentally you can't use the HALT or TRAP interrupts as these are reserved for use with the debug unit.

HTH!

[adib]

Posted on September 01, 2004 at 09:37

Thanks, that was the problem.

I disconnected my clock from pin #9 and I see that the inDART-STX supplys clock there.

Gilat.