RTX51 TINY: User Interrupt Function does not work

Information in this article applies to:

• C51, all versions

QUESTION

The RTX51 Tiny User's Guide states that C51 interrupt functions can be used in parallel with the kernel. However, my RTX51 Tiny application hangs when I enable the following interrupt function.

void adc_int (void) interrupt 0 using  1 {
  unsigned char msb, lsb;

  msb = rd_msb;
  lsb = rd_lsb;
  msb = msb<<4;
  lsb = lsb>>4;
  adc_v= msb | lsb;
  isr_send_signal(4);
}

What could be the problem?

ANSWER

RTX51 Tiny does work in parallel with interrupt functions. However, RTX51 Tiny, by default, uses register bank 1 for its timer 0 interrupts. The register bank configuration may be changed in CONF_TNY.A51.

When using the default timer interrupt setting for RTX51 Tiny, you must ensure that you use a different register bank for other interrupts. Changing your interrupt function definition to:

void adc_int (void) interrupt 0 using  2 {

should solve the problem.

MORE INFORMATION

• Refer to Interrupts in the RTX51 Tiny User's Guide.

SEE ALSO

• RTX51 TINY: Interrupts Stop Working
• RTX51 TINY: Hardware Timer Interrupt fails

Last Reviewed: Thursday, February 25, 2021