topic Re: How to set/arrange KL03 interrupt priority in Kinetis Microcontrollers

How to set/arrange KL03 interrupt priority

tigerlo — Wed, 12 Apr 2017 05:51:31 GMT

Dear Sir,

I want set KL03 PortB interrupt's priority is higher than RTC .

void NVIC_SetPriority(IRQn_Type IRQn, uint32_t priority)

1. uint32_t priority : -1,-2 , 3 , 72 , 116 what is the priority in them ?

2. if I use NVIC_SetPriority(IRQn_Type IRQn, uint32_t priority) to set the priority , then it can work as these priority properly ? or is there any other code I need to added then it can work as it's priority ?

Re: How to set/arrange KL03 interrupt priority

mjbcswitzerland — Wed, 12 Apr 2017 12:34:56 GMT

The values for priority that are being displayed with whichever tool is being used can't be correct. The only possibilities are (0x00 << 6) = 0x00 [decimal 0]

(0x01 << 6) = 0x40 [decimal 64]

(0x02 << 6) = 0x80 [decimal 128]

(0x03 << 6) = 0xc0 [decimal 192]

for Cortex m0+ devices (4 priority levels), whereby the Cortex m0+ only implements these 2 bits in the register so all otherwise will read '0'

I don't know the routine
void NVIC_SetPriority(IRQn_Type IRQn, uint32_t priority);

but expect that it will either want the values 0,1,2 or 3 as priority, or else will require (0, (1 << 6), (2 << 6) or (3 << 6)) depending on how it is internally implemented.
If it is not documented or obvious from examples you will need to study its code.

Regards

Mark

Professional support for Kinetis: http://www.utasker.com/index.html
Remote desktop one-on-one coaching: http://www.utasker.com/services.html
Getting started to expert videos: https://www.youtube.com/results?search_query=utasker+shorts

Re: How to set/arrange KL03 interrupt priority

tigerlo — Fri, 14 Apr 2017 14:50:37 GMT

Mark,

Thanks for your reply, I still have something don't understand.

1. I want set the Port B interrupt higher than RTC Alarm interrupt , what the IPR 5 and IPR 7 value set ?

IPR5 RTC Alarm

IRQ0=4

IPR7 Port

IRQ3=0

2. Is the priority IRQ0=0 higher than IRQ0=1 or 2 or 3 ？

Re: How to set/arrange KL03 interrupt priority

mjbcswitzerland — Fri, 14 Apr 2017 18:26:03 GMT

0 is highest priority and 3 is lowest.

Regards

Mark

Re: How to set/arrange KL03 interrupt priority

tigerlo — Sat, 15 Apr 2017 11:54:01 GMT

Mark，

Thanks for your answer. it's very helpful.

I want set the Port B interrupt higher than RTC Alarm interrupt , Is that correct?

==》Set IPR5 IRQ=4 (Lowest , RTC Alarm Interrupt) & IPR7 IRQ3=0. (Highest, Port B Interrupt)

IPR5 RTC Alarm

IRQ0=4

IPR7 Port

IRQ3=0

Tiger

Re: How to set/arrange KL03 interrupt priority

mjbcswitzerland — Sat, 15 Apr 2017 15:17:21 GMT

With IRQ0 as 3 instead of 4 it looks to be correct.

In the uTasker project it is done like this:

#define PRIORITY_RTC 3
#define PRIORITY_PORTB 0

fnEnterInterrupt(irq_RTC_ALARM_ID, PRIORITY_RTC, _rtc_handler);

fnEnterInterrupt(irq_PORTB_ID, PRIORITY_PORTB, _port_B_isr);

which avoids the head-scratching required in your environment.

Regards

Mark