Interrupt disabling in HCS12 microcontroller

Jagadish — Wed, 16 Sep 2009 19:32:41 GMT

Hello,

I am currently using HCS12x microcontroller and third party operating system(OS) for an application. The OS has two macro's SuspendAllInterrupts() and DisableInterrupts().

I find SuspendAllInterrupts() changes IPL level to 0x07 and does not do anything with I bit.

But DisableInterrupts() changes the I bit value to 1.

My question is, I want to enter a critical region in code.

1. Should I use SuspendAllInterrupts() or DisableInterrupt()

2. What is the difference between these two macro's?

Regards,

Re: Interrupt disabling in HCS12 microcontroller

kef — Thu, 17 Sep 2009 13:54:12 GMT

2. The effects of setting I bit or setting IPL to 7 are almost the same. In first case CPU masks all I-bit maskable interrupts. In the second interrupt controller inhibits all I-bit maskable interrupts.

1. I don't know. In both cases your critical section should end with restoring I-bit and/or restoring IPL.

topic Re: Interrupt disabling in HCS12 microcontroller in S12 / MagniV Microcontrollers

Interrupt disabling in HCS12 microcontroller

Re: Interrupt disabling in HCS12 microcontroller