topic Re: K60 Interrupt Priority in CodeWarrior for MCU

K60 Interrupt Priority

davidzhou — Wed, 31 Aug 2016 19:24:39 GMT

HI,

I have K60 Tower board: MK60FN1M0VLQ12.

In the reference manual, 3.2.2.1 Interrupt priority levels, and table Table 3-5. Interrupt vector assignments show the registers for each interrput. For example:

0x0000_013C 79 63 1 15 FTM1 Single interrupt vector for all sources

If I want to set the interrupt with PRIORITY 1:

I shall use register NVICIPR15, and

NVICIPR15 = 0x01;

Is this correct?

But the code generated by PE wizard:

//Enable Interrupt
NVICIP63 = NVIC_IP_PRI63(0x80);
/* NVICISER1: SETENA|=0x80000000 */
NVICISER1 |= NVIC_ISER_SETENA(0x80000000);
FTM1_SC |= FTM_SC_TOIE_MASK;
_int_install_isr(LDD_ivIndex_INT_FTM1, FC1_OnOverflow, NULL );

Why use NVICIP63 = NVIC_IP_PRI63(0x80); ?

what means to 0x80?

IPR registers contains 4 bits as stated in the section 3.2.2.1 Interrupt priority levels.

I am a little confused. What are priority levels (0-15 with 0 as highest priority?) or priorities from 0 - 0xFF ?

Thank you

David Zhou

Re: K60 Interrupt Priority

Alice_Yang — Thu, 01 Sep 2016 07:10:44 GMT

Hello David,

- Which version of IDE do you used ? I used the CW 10.6.4, when i set the FTM1 priority to

"1" , the generated code is :

/* NVICIP63: PRI63=0x10 */
NVICIP63 = NVIC_IP_PRI63(0x10);

The result is right .

- For this device , one byte(8 bit) support one interrupt priority use the NVIC_IPR register ,

while the low 4 bits have no effect, the default data is "0000" , so only the high 4 bits indicate

the priority . For example , if the priority is "1", the data should be 0x10, not 0x01 .

- About "NVICIPR15" , this is the define register on ARM M4 core, while , in this chip ,

it doesn't defined as this name . As we know , on NVICIPR register includes 4 bytes ,

in this chip , defined all the bytes :

From the RM of K60, we can see FTM1 IRQ is 63, so the result is NVICIP63 = NVIC_IP_PRI63(0x10);

Does this can helps you ?

Have a great day,
Alice

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Re: K60 Interrupt Priority

davidzhou — Thu, 01 Sep 2016 20:53:23 GMT

Hi Alice,

Thank you. That helps.

David Zhou