Revision as of 21:07, 24 August 2013

Action

Enable specified interrupt.

(ATTINY, ATMEGA, ATXMEGA)

Syntax

ENABLE interrupt [, prio]

[, prio] is only for ATXMEGA

Remarks

By default all interrupts are disabled.

The global interrupts master switch is also disabled by default.

If you enable an interrupt, it will only fire if the master interrupt switch is enabled.

You enable this master switch with ENABLE INTERRUPTS.

You can disable it with DISABLE INTERRUPTS.

If an interrupt is executed, the global master switch will be disabled automatically by the hardware.

This is to prevent other interrupts to occur.

When the interrupt routine returns, the processor hardware will automatically enable the master switch so new interrupts may occur.

It depends on the processor how many and which interrupts it has. If you type ENABLE in the editor, you will get a pop up with a list of interrupts you can chose from.

ATTINY & ATMEGA Interrupt List

In normal AVR chips the priority is determined by the interrupts address. The lower the address, the higher the priority.

In the DAT file you can find a list with interrupts and their address.

For example , taken from the m1280def.dat file "

[INTLIST]

count=56

INTname1=INT0,$002,EIMSK.INT0,EIFR.INTF0

INTname2=INT1,$004,EIMSK.INT1,EIFR.INTF1

INTname3=INT2,$006,EIMSK.INT2,EIFR.INTF2

INTname4=INT3,$008,EIMSK.INT3,EIFR.INTF3

INTname5=INT4,$00a,EIMSK.INT4,EIFR.INTF4

INTname6=INT5,$00c,EIMSK.INT5,EIFR.INTF5

INT0 has the highest priority since it has the lowest address (address 2)

Following an Overview where INT0 is used as an example.

Overview

1. You configure an Interrupt

 
On Int0 Int0_isr                                           
Config Int0 = Low Level

2. You enable the specific Interrupt

 
Enable Int0
 

3. Enable all Interrupts

 
Enable Interrupts
 
 
4. You have an Interrupt Service Routine after the "End" with an Return
 

End

' Interrupt Service Routine
Int0_isr:
' so someting.....
Return

XMEGA

The XMEGA has a priority system. You can specify if an interrupt has a low, medium or high priority.

But you MUST enable these priorities  with CONFIG PRIORITY

Config Priority = Static , Vector = Application , Lo = Enabled , Med = Enabled , Hi = Enabled

If you use LO or High priority, they have to be enabled.

If you do not specify a priority, MED will be used.

In the DAT file you can find a list with interrupts and their address.

For example , taken from the "xm128A4Udef.dat file "

INTLIST]

count=95

INTname1=OSCFAIL,$0002,OSC_XOSCFAIL.0,OSC_XOSCFAIL.1        ; XOSC Failure Detection Register

INTname2=PORTC_INT0,$0004,#PORTC_INTCTRL.0,PORTC_INTFLAGS.0

INTname3=PORTC_INT1,$0006,#PORTC_INTCTRL.2,PORTC_INTFLAGS.1

INTname4=PORTR_INT0,$0008,#PORTR_INTCTRL.0,PORTR_INTFLAGS.0

INTname5=PORTR_INT1,$000A,#PORTR_INTCTRL.2,PORTR_INTFLAGS.1

INTname6=DMA_CH0,$000C,#,DMA_CH0_CTRLB.0,DMA_CH0_CTRLB.4

INTname7=DMA_CH1,$000E,#,DMA_CH1_CTRLB.0,DMA_CH1_CTRLB.4

INTname8=DMA_CH2,$0010,#,DMA_CH2_CTRLB.0,DMA_CH2_CTRLB.4

INTname9=DMA_CH3,$0012,#,DMA_CH3_CTRLB.0,DMA_CH3_CTRLB.4

INTname10=RTC_OVF,$0014,#RTC_INTCTRL.0,RTC_INTFLAGS.0

INTname11=RTC_COMP,$0016,#RTC_INTCTRL.2,RTC_INTFLAGS.1

Example with PORTC_INT0
 
On Portc_int0 portc_isr
Enable Portc_int0 , Hi
 

In ATXMEGA there is an example for Pin Interrupt.

See also

DISABLE , ON , CONFIG PRIORITY, ATXMEGA

Example

$regfile = "attiny25.dat"
$crystal = 1000000 ' 1MHz
$hwstack = 10
$swstack = 0
$framesize = 24
 
 
On Int0 Int0_isr ' INT0 will be the wake-up source for Powerdown Mode
Config Int0 = Low Level ' External Pull-up (47K) on Portb.2
Enable Int0
 
'###############################################################################
Do
 Wait 3 ' now we have 3 second to measure the Supply Current in Active Mode
 
 Enable Interrupts
 
 ' Now call Powerdown function
 Config Powermode = Powerdown
 
 'Here you have time to measure PowerDown current consumption until a Low Level on Portb.1 which is the PowerDown wake-up
Loop
'###############################################################################
End
 
 
Int0_isr:
' wake_up
Return