topic Re: S08QE8 Background Debug Mode in 8-bit Microcontrollers

S08QE8 Background Debug Mode

DavidoBG — Mon, 15 Dec 2008 15:55:46 GMT

I try to program my MCU S08QE8 with cyclone pro but i have error message when i try to connect emulator to MCU
Loading Target ...
Windows NT detected.
CYCLONE PRO detected - Flash Version 8.09
Frequency change to ~0hz.
Frequency change to ~0hz.
CYCLONE PRO detected - Flash Version 8.09
Frequency change to ~0hz.
Frequency change to ~0hz.
Frequency change to ~0hz.
Frequency change to ~0hz.
Frequency change to ~0hz.
Frequency change to ~8032hz.

Error: Can not enter background mode.

I check my RESET (Pin 1 of MCU) and BKGD (pin 2 of MCU) signals
On Pin 1 i have 0.4V i thonk OK to do reset.
On pin 2, i have 0.7V!!!
In fact i directly connect PIN 1 of BDM connector from Cyclone to Pin 2 of MCU. Is it correct?
I used an external power to supply MCU but i connect GND of MCU to Pin 2 of BDM connector

Somebody ou somewhere can i find some descriptions, explanation about connections between cyclone emulator and MCU S08QE8?

thanks

David

Re: S08QE8 Background Debug Mode

celsoken — Mon, 15 Dec 2008 21:20:03 GMT

Dear Davido,

BDM physical interface is quite simple, it uses mainly BKGD.
In order to enter BKGD mode you have to have BKGD in 0V and reset the uC.
The problem is that sometimes reset pin is not programmed as that.
The only way to assure this is thru pwr-up reset.

Suggestion from someone who has burned more than 8 EVB BDMs: use 0.1A PPTCs in series with GND(2), BKGD(1), RST(4) and VDD(6 - if you use it). Pullups to VDD from RST and BKGD are nice too.

Cheers,

Celso

Re: S08QE8 Background Debug Mode

alexod — Tue, 23 Dec 2008 09:40:25 GMT

I used an external power to supply MCU but i connect GND of MCU to Pin 2 of BDM connector

It might just be the way you phrased it but, you do have your external power supply's ground connected as well don't you?