ATmega16A Atmel Corporation, ATmega16A Datasheet - Page 68

• Manufacturer Part Number: ATmega16A
• Manufacturer: Atmel Corporation

Specifications of ATmega16A

• Flash (kbytes): 16 Kbytes
• Pin Count: 44
• Max. Operating Frequency: 16 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 32
• Ext Interrupts: 3
• Usb Speed: No
• Usb Interface: No
• Spi: 1
• Twi (i2c): 1
• Uart: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 15
• Analog Comparators: 1
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 1
• Eeprom (bytes): 512
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 2.7 to 5.5
• Operating Voltage (vcc): 2.7 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 3
• Output Compare Channels: 4
• Input Capture Channels: 1
• Pwm Channels: 4
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

13.1.2
68
ATmega16A
MCUCSR – MCU Control and Status Register
low level interrupt is selected, the low level must be held until the completion of the currently
executing instruction to generate an interrupt.
Table 13-1.
• Bit 1, 0 – ISC01, ISC00: Interrupt Sense Control 0 Bit 1 and Bit 0
The External Interrupt 0 is activated by the external pin INT0 if the SREG I-flag and the corre-
sponding interrupt mask are set. The level and edges on the external INT0 pin that activate the
interrupt are defined in
edges. If edge or toggle interrupt is selected, pulses that last longer than one clock period will
generate an interrupt. Shorter pulses are not guaranteed 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.
Table 13-2.
• Bit 6 – ISC2: Interrupt Sense Control 2
The Asynchronous External Interrupt 2 is activated by the external pin INT2 if the SREG I-bit and
the corresponding interrupt mask in GICR are set. If ISC2 is written to zero, a falling edge on
INT2 activates the interrupt. If ISC2 is written to one, a rising edge on INT2 activates the inter-
rupt. Edges on INT2 are registered asynchronously. Pulses on INT2 wider than the minimum
pulse width given in
Shorter pulses are not guaranteed to generate an interrupt. When changing the ISC2 bit, an
interrupt can occur. Therefore, it is recommended to first disable INT2 by clearing its Interrupt
Enable bit in the GICR Register. Then, the ISC2 bit can be changed. Finally, the INT2 Interrupt
Flag should be cleared by writing a logical one to its Interrupt Flag bit (INTF2) in the GIFR Reg-
ister before the interrupt is re-enabled.
Bit
Read/Write
Initial Value
ISC11
ISC01
0
0
1
1
0
0
1
1
ISC10
ISC00
Interrupt 1 Sense Control
Interrupt 0 Sense Control
0
1
0
1
0
1
0
1
R/W
JTD
7
0
“External Interrupts Characteristics” on page 297
Description
The low level of INT1 generates an interrupt request.
Any logical change on INT1 generates an interrupt request.
The falling edge of INT1 generates an interrupt request.
The rising edge of INT1 generates an interrupt request.
Description
The low level of INT0 generates an interrupt request.
Any logical change on INT0 generates an interrupt request.
The falling edge of INT0 generates an interrupt request.
The rising edge of INT0 generates an interrupt request.
Table
ISC2
R/W
6
0
13-2. The value on the INT0 pin is sampled before detecting
R
5
–
0
JTRF
R/W
4
WDRF
R/W
3
See Bit Description
BORF
R/W
2
EXTRF
will generate an interrupt.
R/W
1
PORF
R/W
0
8154B–AVR–07/09
MCUCSR