MON08 on 908JB16: Soft reset problem

[MrBean]

Hi,

I'm using a MON08 interface on 908JB16's.

Everything works fine, i can program, step, run, read flash&RAM etc.

But.. some of my boards exhibit a annoying problem:

Soft reset doesnt work:

Attempting soft reset of HC08 device ... Unsuccessful.
Starting powerdown reset sequence ...

Only on some of my boards... Others give:

Attempting soft reset of HC08 device ...  Success.(RSR=$xx)

There is no difference between boards with a working soft reset and ones that wont.

Same hardware, same cpu (datecode), same flash contents, same cable... 

Any idea's as to what might cause this ?

Message Edited by MrBean on 2008-10-16 03:33 PM

[MrBean]

I suspect it to be a timing problem.

(nRST pin capacitor differences, osc startup time, ...)

Is there a way to change the timeout for such a reset ?

I'll try spying on the PTA0 communication to see what happens.

[MrBean]

Ok.

The following happens on PTA0:

(> indicates from PC to JB16)

(< indicates from JB16 to PC)

>4a <4a >fe <fe >fb <fb <10
>4a <4a >ff <ff >f6 <f6 <f3
>4a <4a >ff <ff >f7 <f7 <f2
>4a <4a >fe <fe >01 <01 <00
>4a <4a >fe <fe >fb <fb <10
>4a <4a >10 <10 >00 <00 <ad
>4a <4a >10 <10 >01 <01 <ad
>0c <0c <00 <fa
>49 <49 >00 <00 >fe <fe >10 <10 >19 <19 >00 <00 >28 <28 >f3 <f3 (rest of security bytes) <00

The difference between resetting and not-resetting boards is that the ones that won't reset do not echo anything after >f3 (first security byte) sent by the PC.

This security byte is correct. Power-on-reset and subsequently entering monitor mode does work.

An ideas ? Anyone ?

[MrBean]

Found something strange again:

if i do not enter a valid secuity code (hiwave.exe nags about device secured, cannot read flash)

Then I am able to reset a board that wouldnt reset with security code.

Veeery strange.

[MrBean]

No ideas why ?

Should i ask it elsewhere eg. a service request ?

[Lundin]

I'm not sure what a "soft reset" is. I suppose I'd call writing the wrong value to the COP a soft reset, and everything involving the pin a "hard" reset.

Unless my memory fails, the MON08 interface is using the reset pin and nothing else.

Spontaneously, it sounds like a hardware issue, especially since MON08 is the worst programming interface I have ever encountered, it is extremely error-prone.

What you should check is that you have correct pull resistors on all pins required by your HC08 derivate. If one of them lacks a pull resistor, or has the wrong one, weird things will happen.

You also need the programming voltage "Vtst" on the IRQ pin. This voltage needs to be at least 4V higher than your supply voltage, so at least 9V on a common 5V system. Check this voltage on the IRQ pin on all boards you are having problems with.

The best solution is of course to port to S08 and I promise you that the problem will disappear

[MrBean]

The interface hardware between PTA0 and an RS232 port is custom build.

It has no reset pin control.

The MON08 works 100% error free apart from the above problem.

The soft reset is the "reset target (Ctrl-R)" in hiwave.exe, i presume that it is command driven thru PTA0.

It looks like an illegal adddress reset as RSR always contains bit3=1 (ILAD) after that.

Vdd is 5.00V, Vtst is 7.80V  ( Vtst>Vdd+2.50V and Vtst<8V (Abs MAX) as per technical datasheet)

PTA0,PTA1,PTA3 and PTE3 have 10k pullup, PTA2 has 10k pulldown, as they should.

Of course the first thing i checked is that these are correct on all boards.

The problem is not spontaneous as some (of the indentical) boards constistantly wont reset and some consitantly will (on request).

Message Edited by MrBean on 2008-10-16 05:30 PM

Message Edited by MrBean on 2008-10-16 05:32 PM