Electronic Components Datasheet Search
  English  ▼

Delete All
ON OFF
ALLDATASHEET.COM

X  

Preview PDF Download HTML

ATMEGA16-16MC Datasheet(PDF) 64 Page - ATMEL Corporation

Part No. ATMEGA16-16MC
Description  8-bit AVR Microcontroller with 16K Bytes In-System Programmable Flash
Download  315 Pages
Scroll/Zoom Zoom In 100% Zoom Out
Maker  ATMEL [ATMEL Corporation]
Homepage  http://www.atmel.com
Logo 

ATMEGA16-16MC Datasheet(HTML) 64 Page - ATMEL Corporation

Zoom Inzoom in Zoom Outzoom out
 64 / 315 page
background image
64
ATmega16(L)
2466E–AVR–10/02
External Interrupts
The External Interrupts are triggered by the INT0, INT1, and INT2 pins. Observe that, if
enabled, the interrupts will trigger even if the INT0..2 pins are configured as outputs.
This feature provides a way of generating a software interrupt. The external interrupts
can be triggered by a falling or rising edge or a low level (INT2 is only an edge triggered
interrupt). This is set up as indicated in the specification for the MCU Control Register –
MCUCR – and MCU Control and Status Register – MCUCSR. When the external inter-
rupt is enabled and is configured as level triggered (only INT0/INT1), the interrupt will
trigger as long as the pin is held low. Note that recognition of falling or rising edge inter-
rupts on INT0 and INT1 requires the presence of an I/O clock, described in “Clock
Systems and their Distribution” on page 22. Low level interrupts on INT0/INT1 and the
edge interrupt on INT2 are detected asynchronously. This implies that these interrupts
can be used for waking the part also from sleep modes other than Idle mode. The I/O
clock is halted in all sleep modes except Idle mode.
Note that if a level triggered interrupt is used for wake-up from Power-down mode, the
changed level must be held for some time to wake up the MCU. This makes the MCU
less sensitive to noise. The changed level is sampled twice by the Watchdog Oscillator
clock. The period of the Watchdog Oscillator is 1 µs (nominal) at 5.0V and 25
°C. The
frequency of the Watchdog Oscillator is voltage dependent as shown in “Electrical Char-
acteristics” on page 285. The MCU will wake up if the input has the required level during
this sampling or if it is held until the end of the start-up time. The start-up time is defined
by the SUT fuses as described in “System Clock and Clock Options” on page 22. If the
level is sampled twice by the Watchdog Oscillator clock but disappears before the end
of the start-up time, the MCU will still wake up, but no interrupt will be generated. The
required level must be held long enough for the MCU to complete the wake up to trigger
the level interrupt.
MCU Control Register –
MCUCR
The MCU Control Register contains control bits for interrupt sense control and general
MCU functions.
• Bit 3, 2 – ISC11, ISC10: Interrupt Sense Control 1 Bit 1 and Bit 0
The External Interrupt 1 is activated by the external pin INT1 if the SREG I-bit and the
corresponding interrupt mask in the GICR are set. The level and edges on the external
INT1 pin that activate the interrupt are defined in Table 34. The value on the INT1 pin is
sampled before detecting edges. If edge or toggle interrupt is selected, pulses that last
longer than one clock period will generate an interrupt. Shorter pulses are not guaran-
teed to generate an interrupt. If low level interrupt is selected, the low level must be held
until the completion of the currently executing instruction to generate an interrupt.
Bit
765
432
10
SM2
SE
SM1
SM0
ISC11
ISC10
ISC01
ISC00
MCUCR
Read/Write
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Initial Value
0
0
0
0
0
0
0
0
Table 34. Interrupt 1 Sense Control
ISC11
ISC10
Description
0
0
The low level of INT1 generates an interrupt request.
0
1
Any logical change on INT1 generates an interrupt request.
1
0
The falling edge of INT1 generates an interrupt request.
1
1
The rising edge of INT1 generates an interrupt request.


Html Pages

1  2  3  4  5  6  7  8  9  10  11  12  13  14  15  16  17  18  19  20  21  22  23  24  25  26  27  28  29  30  31  32  33  34  35  36  37  38  39  40  41  42  43  44  45  46  47  48  49  50  51  52  53  54  55  56  57  58  59  60  61  62  63  64  65  66  67  68  69  70  71  72  73  74  75  76  77  78  79  80  81  82  83  84  85  86  87  88  89  90  91  92  93  94  95  96  97  98  99  100   ...More


Datasheet Download




Link URL




Privacy Policy
ALLDATASHEET.COM
Does ALLDATASHEET help your business so far?  [ DONATE ]  

About Alldatasheet   |   Advertisement   |   Datasheet Upload   |   Contact us   |   Privacy Policy   |   Alldatasheet API   |   Link Exchange   |   Manufacturer List
All Rights Reserved© Alldatasheet.com


Mirror Sites
English : Alldatasheet.com  |   English : Alldatasheet.net  |   Chinese : Alldatasheetcn.com  |   German : Alldatasheetde.com  |   Japanese : Alldatasheet.jp
Russian : Alldatasheetru.com  |   Korean : Alldatasheet.co.kr  |   Spanish : Alldatasheet.es  |   French : Alldatasheet.fr  |   Italian : Alldatasheetit.com
Portuguese : Alldatasheetpt.com  |   Polish : Alldatasheet.pl  |   Vietnamese : Alldatasheet.vn