How to use timer overflow interrupt

dan23 — Fri, 26 Sep 2008 14:09:08 GMT

Hi I’m new using codewarrior and the HCS12 T-board, onboard is the mc9s12dp512 chip.

I want to use the timer to count 1 millisecond till a overflow occurs. When a overflow occurs I want to use an interrupt to call a sub routine.

Here is a bit of my code. This interrupt implementation doesn’t work. What am I doing wrong?

void SetTimer(void)

{

TCNT = 0xE0C0;

TSCR1 = 0x90;

}

interrupt 16 void TimerCount(void)

{

ms++; //global variable

TCNT = 0xE0C0;

}

when I built my project I’ll get the following error message.

Link error: L1907: fixup overflow in _Vector_16, TimerCount type 1, at offset 0x0

Could anyone help me with this problem?

Greetings dan23

Re: How to use timer overflow interrupt

stanish — Fri, 26 Sep 2008 14:54:23 GMT

Hi dan23,

Similar issue was already discussed here. You should ensure your ISR routine is placed in NON_BANKED memory. For more information I'd invite you to see e.g.:

http://forums.freescale.com/freescale/board/message?board.id=CW816COMM&message.id=3698&query.id=195937#M3698

Regards,

stanish