I'm working on interrupts with i.MX6 processor.
As #RodBorras said in this thread:
"This is my understanding of how the MX6Q GPIO interrupts work:
a) GPIO1 (32 pins) through GPIO7 (32 pins) can be configured to generate interrupts when the pins are set to inputs
b) GPIO2 through GPIO7 do not have an "ARM interrupt" for each pin, but rather for the OR'ed results of 16 pins
==> e.g. GPIO2 will cause an "ARM IRQ 100" if there is a valid interrupt on any pin within 0-15
==> e.g. GPIO2 will cause an "ARM IRQ 101" if there is a valid interrupt on any pin within 16-31
==> So even though GPIO2 can monitor 32 pins for activity, the ARM Core will only see 1 of 2 IRQs happen (#100 or #101)
c) GPIO1 has the same functionality as described in b), but also some further granularity: its bottom 8 pins (0-7) will cause 8 specific "ARM interrupts"
==> GPIO1_0 will cause an "ARM IRQ 97", and so on for pins 1,2,3,4,5,6; GPIO1_7 will cause an "ARM IRQ 90"
==> for GPIO1_8 through GPIO1_31, these can only be seen through "ARM IRQ98" for pins 0-15, or "ARM IRQ99" for pins 16-31"
So if we take the example of two interrupts of the same group (for example, two pins between 0 and 15 of GPIO2), how can we know which pin triggered the interrupt?
Thanks for your help!
From NXP TechSupport answer: "Interrupt source can be obtained reading GPIOx_ISR register described in sect.28.5.7 GPIO interrupt status register (GPIOx_ISR)"
Here is the corresponding register description from this document.
Related
I want to enable the PA8 pin in a processor (Atmel SAM3X / SAM3A). I have set PIOA_MDERp[7]=0 and PIOA_MDDR[7]=0 and PIO_OER[7]=0 and PIO_ODR[7]=1, so that the tri-state buffer will no longer send data out of the pin, and the pin is enabled to receive data from the environment and to send interrupts if needed. I also want to set my interrupt to rising edge, so I also did PIOA_RHLSR[7]=1 and PIOA_FELLSR[7]=0 and also PIO_ESR[7]=1 and PIOA_LSR[7]=0.
My problem now is how to modify NVIC registers so that this interrupt is enabled. I mean, on a rising edge on this pin, the state of this pin is pending, and then the changes I will apply to NVIC causes this pending state to active state.
My interrupt group priority and subgroup priority are both 3.
I know how to modify Interrupt set-enable register, interrupt clear-enable register, application interrupt and reset control register, and interrupt priority register. Still, my problem is that now I don't have any number for interrupts from this specific pin (PIOA8), so it is different from the time I had my interrupt number (from 1 to 240), and so I could know which register in the NVIC I should modify.
Thanks for your help.
I am trying to make it so that then PINB7 is pressed (which is pin of botton) LED to light up.
PINB7 is PCINT8 on board.
So i set
PCICR|=(1<<1);//enable interrupts for pins 14-8
sei();
PCMSK1|=(<<PCINT8); // mask for pin 8
i don't get what vector i should use in ISR. From what i saw I should just do PCINT8_vect, however vector doesn't get highlighted like then i use "TIMER2_COMPB_vect".So does PCINT8 vector not exist or is there way to use PCINT0 and 1 for this?
Apparently , on mega328pb , there is no vectors for individual pin interrupts but there are vectors for PCIE0,1,2,3.
0- bits 0:7
1-8:14
2-16:23
3-24:27
so if u want to use interrupt for pin b7.
PB7 is PCINT7(can be seen in chapter about i/o ports).
So id have to enable PCIE0 in PCIRC register, correct mask it TMSK0. and use ISR(PCINT0_vect).
But if you have interrupt on PCINT6 and PCINT7 , you need if else in ISR to determine which of 2 pins triggered interrupt
I am facing problems using sc16is750 breakout board. I want to use the interrupt method mentioned in the datasheet. According to which, the IRQ pin should be active low whenever Rx or Tx pins are active, and an Interrupt should be generated.
But the IRQ pin remains high nonetheless. I have set up an external 1k ohm pull-up resistor as mentioned with 3.3v VDD.
My goal is to use vk16e gps module through spi pins on an arduino uno. I have set up the low interrupt on digital pin 2 and it is working fine. If I manually connect this pin to the ground, the gps data appears successfully. But not with the IRQ pin.
I had a similar issue. Finally I found out that the interrupt pin on the breakout board is not connected to the 2kOhm IRQ pull up.
I added a white wire and now it works fine.
I would like to implement a pulse-sensitive, aka edge-triggered, interrupt on an LPC1759 microcontroller. In the UM10360.pdf datasheet and ARM Cortex-M3 user guide, it says that interrupts can be triggered based on level- or pulse-sensitive behavior, but I am unable to find how to set this to be pulse-sensitive. Can someone please tell me where to set this?
For my particular application(interfacing the LPC1759 with an AD7794 ADC), I would like to trigger an interrupt based on the falling edge of the MISO pin. Although it is not explicitly stated that the interrupt is trigger on the MISO value, I am assuming this based on the fact that, of the four SPI signals, the MISO is the only input to the microcontroller. Please let me know if this is not correct.
See UM10360.pdf, chapter 9.5.6: "GPIO interrupt registers". You can enable rising and falling edge interrupts only on port 0 and 2 pins. The interrupt vector is the same as external interrupt 3.
How can I increase the USART baud rate to 2Mbps, 3Mbps or 4Mbps. I am using STM32L151RCT6A, I am able to run to 921600. I have set clock with PLL 32MHz. On the datasheet it is given, which shows it is possible, Has anyone ever done this?
The datasheet only outlined the specific part and its peripheral set and electrical characteristics. For information on how to use the device you need the Reference Manual. This gives the following equation for baud rate:
Tx/Rx baud = CK_APB1 / (8 x (2 - OVER8) x USARTDIV)
Where USARTDIV is an unsigned fixed point number that is coded on the USART_BRR register.
When OVER8=0, the fractional part is coded on 4 bits and programmed by the
DIV_fraction[3:0] bits in the USART_BRR register
When OVER8=1, the fractional part is coded on 3 bits and programmed by the
DIV_fraction[2:0] bits in the USART_BRR register, and bit DIV_fraction3 must be kept
cleared.
The USARTs are on the APB1 bus, Figure 12 in the reference manual is the clock tree, which shows how the APB1 clock is derived from the PLL clock. The maximum APB1 clock is 32MHz. OVER8=1 is required for higher speeds, giving:
baud = 32X106 / (USARTDIV x 8).
So USARTDIV = 32X106 / (baud x 8)
For 4Mbps therefore, USARTDIV=1 (see table 138 S.No.12 for details). For 2Mps, USARTDIV=2. To achieve 3Mbps you will have to reduce the APB1 clock to 24MHz and set USARTDIV=1 (see table 131). But note that the clock rate changes for all other APB1 peripherals too.
The simplest way to correctly program the USART baud rate is via the STM32L1xx standard peripheral library. Also to determine the correct peripheral clock settings (and more), and generate initialisation code, you can use STM's MicroXplorer tool.