8-bit MicrocontrollersのトピックRe: RTC Interrupt handling on HC08-LK24

RTC Interrupt handling on HC08-LK24

lc_hc — Mon, 11 May 2009 16:09:26 GMT

Hi there,

i use the RTC to generate a periodic 1 second interrupt. Everythings fine, but the ISR itself dosen´t seem to work correct. I run the code in the Simulator from CW for HC08 and then the cursor is stuck into the RTC isr, until i disable RTIE bit. Do I need to Acknowledge the RTC interrupt ? And if yes, then how ? I searched thru www and the datasheet, up to now without success.

hanks for your help in advance.

greetings,

Simon

Re: RTC Interrupt handling on HC08-LK24

eckhard — Mon, 11 May 2009 17:34:14 GMT

Hello,

you must ackknowledgetheinterrupt by writing to the RTIACK bit in the SRTISC Register

Eckhard

Re: RTC Interrupt handling on HC08-LK24

lc_hc — Mon, 11 May 2009 18:03:16 GMT

@Eckhard:

thanks for your comment. Unfortunately theres no RTIACK Bit and even no RTI Status Register. But this one ( RTCSR ):

SECF — Second Flag

This clearable, read-only bit is set on every increment of the second

counter. When the SECIE bit in RTCCR1 is set, SECF generates a

CPU interrupt request. In normal operation, clear the SECF bit by

reading RTCSR with SECF set and then reading the second register

(SECR). Reset clears SECF.

1 = Second counter incremented

0 = No second counter incremented

Is this used to acknowledge the irq from the ISR ?

thanks.

Re: RTC Interrupt handling on HC08-LK24

peg — Mon, 11 May 2009 19:29:07 GMT

Hello and welcome to the fora, lc-hc

If you are generating interrupts by having the SECIE bit set in the RTCCR1 register, then yes, this is what you have to do to clear the SECF flag which is the source of that interrupt.

Like Eckard, on first read of your post I was thinking of the RTI too.