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AT90S8515 reset and Watchdogtimer issues?

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UroBoros

UroBoros

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at90s8515 versus pic

Hai
Using code vision and AVR studio.

tried to run a timer programe originally done for 4433 .I have converted that programe to 8515 in Codevision.

programmed the chip using Pony prog ISp dongle.

Seems to be programmed, The code is running means seems at least starting.But not predictable.Some times starting sometimes not starting.

Any resetting issues?

I have given VCC to 40,GND to 20 and 10K pull up and .1uF at reset pin.

What about watchdog timer.Is it enabled by default.Or disabled.Or is there any configuration bits like PIC.I am using 4MHZ crystal


Please suggest

picstudent
 

at90s8515 price india

Picstudent said:
Hai
What about watchdog timer.Is it enabled by default.Or disabled.Or is there any configuration bits like PIC
Click to expand...

The WDT Initial state of AT90S4414/8515 is disabled at power-up and similar with Safety level 0 of ATMega8515 (FUSE bit S8515C programmed "0" and WDTON unprogrammed "1").

If you're using PonyProg typing CTRL+S will bring up Security and Configuration bits window. As you can see, only power-up status of ATMega8515's whatchdog can be controlled through FUSE bits (like PIC).

The value of watchdog timeout is regardless of your XTAL because the watchdog timer is feeded by a separate 1MHz On-chip oscillator through a timer prescaler.
The only thing that counts is the value of power supply (Time-out period increases with decreasing VCC).

Picstudent said:
.Some times starting sometimes not starting.
Click to expand...

Who is the witness ? I mean what leads you to believe it's working or not ?
 

    UroBoros

    UroBoros

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at90s8515 india availability

Hai

Thanks for the reply.

Checked in pony Prog .Both the fuse bits are clear. Not checked.

I felt it is working because sometimes if I repeatedly switch it on and off it shows the initial display sometimes,Sometimes non sense on 7 Segment LEDS.


Crystal is ok I think because it is getting programmed and verified OK.

I have tried by programming from Pony Prog as well as Codevision directly.

Thanks a lot.
 

Picstudent said:
Checked in pony Prog .Both the fuse bits are clear. Not checked.
Click to expand...

If you're using AT90S8515 then the fuse that you've seen in Security and Configuration bits window are the lock bits which has nothing to do with the watchdog disable/enable.

Picstudent said:
I felt it is working because sometimes if I repeatedly switch it on and off it shows the initial display sometimes,Sometimes non sense on 7 Segment LEDS.
Click to expand...

I would suggest to load an ordinary blinking LED program to test the microcontroller and if everything goes OK then check carefully your code.
 

    UroBoros

    UroBoros

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Hai

Thanks silvio for the replys.


I have solved the issue.Actually it was my software mistake .I hve tried the same hex by mistake of 4433 into this one.That may be the reason by that erratic behavier. I have tried that LED method and located the problem.

When I converted the programe into 8515 timer1 compare registers were incompatable with 4433. So when each compare interupt was excuted it vectored to the reset vecor by codevision.So the programe didint seems to start at all.

It is ok now. But still wonder how something seems to display sometimes..

Thanks a lot

picstudent
 

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