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PIT0 Timer Module, and GPIO Direct Acess

Question asked by Dao Yan Lim on Feb 28, 2017
Latest reply on Mar 8, 2017 by Dao Yan Lim

Hi,

 

I am using TWR-K60N512 with PK60DN512Z VMD10 chip, and Codewarrior 10.5 IDE with MQX 3.8. I have three questions:

 

1) Does the MQX 3.8 kernel still use PIT0 as tick reference? I'm currently using it to generate a pulse train and it works fine, just curious what effects it might have if it still is actually still being used as tick reference simultaneously.

 

2) Why doesn't simple GPIO direct access work anymore in MQX? The code is shown below, which works in a baremetal project.

 

3) Any drawback or advantages in using MQX I/O in interrupt? For example, I'm able to write high or low in an interrupt using 'ioctl(port_file2, GPIO_IOCTL_WRITE_LOG1, NULL );' since GPIO direct access doesn't work...

 

SIM_SCGC5 |= SIM_SCGC5_PORTA_MASK | SIM_SCGC5_PORTB_MASK | SIM_SCGC5_PORTC_MASK | SIM_SCGC5_PORTE_MASK;

PORTC_PCR18 |= PORT_PCR_MUX(1); 
GPIOC_PDDR |= GPIO_PIN(18);
GPIOC_PSOR |= GPIO_PIN(18); 

GPIOC_PTOR |= GPIO_PDOR_PDO(GPIO_PIN(18));

 

Thanks.

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