ATmega64C1 Automotive Atmel Corporation, ATmega64C1 Automotive Datasheet - Page 19

• Manufacturer Part Number: ATmega64C1 Automotive
• Manufacturer: Atmel Corporation

Specifications of ATmega64C1 Automotive

• Flash (kbytes): 64 Kbytes
• Pin Count: 32
• Max. Operating Frequency: 16 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 12
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 27
• Ext Interrupts: 27
• Usb Speed: No
• Usb Interface: No
• Spi: 1
• Uart: 1
• Can: 1
• Lin: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 11
• Adc Resolution (bits): 10
• Adc Speed (ksps): 125
• Analog Comparators: 4
• Resistive Touch Screen: No
• Dac Channels: 1
• Dac Resolution (bits): 10
• Temp. Sensor: Yes
• Crypto Engine: No
• Sram (kbytes): 4
• Eeprom (bytes): 2048
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 150
• I/o Supply Class: 2.7 to 5.5
• Operating Voltage (vcc): 2.7 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 2
• Output Compare Channels: 4
• Input Capture Channels: 1
• Pwm Channels: 4
• 32khz Rtc: No
• Calibrated Rc Oscillator: Yes

3.8.2
7647G–AVR–09/11
Interrupt Response Time
When using the SEI instruction to enable interrupts, the instruction following SEI will be exe-
cuted before any pending interrupts, as shown in this example.
The interrupt execution response for all the enabled AVR interrupts is four clock cycles mini-
mum. After four clock cycles the program vector address for the actual interrupt handling
routine is executed. During this four clock cycle period, the Program Counter is pushed onto
the Stack. The vector is normally a jump to the interrupt routine, and this jump takes three
clock cycles. If an interrupt occurs during execution of a multi-cycle instruction, this instruction
is completed before the interrupt is served. If an interrupt occurs when the MCU is in sleep
mode, the interrupt execution response time is increased by four clock cycles. This increase
comes in addition to the start-up time from the selected sleep mode.
A return from an interrupt handling routine takes four clock cycles. During these four clock
cycles, the Program Counter (two bytes) is popped back from the Stack, the Stack Pointer is
incremented by two, and the I-bit in SREG is set.
Assembly Code Example
C Code Example
Assembly Code Example
C Code Example
in r16, SREG
cli
sbi EECR, EEMWE
sbi EECR, EEWE
out SREG, r16
char cSREG;
cSREG = SREG;
/* disable interrupts during timed sequence */
_CLI();
EECR |= (1<<EEMWE); /* start EEPROM write */
EECR |= (1<<EEWE);
SREG = cSREG;
sei
sleep; enter sleep, waiting for interrupt
; note: will enter sleep before any pending
; interrupt(s)
_SEI(); /* set Global Interrupt Enable */
_SLEEP(); /* enter sleep, waiting for interrupt */
/* note: will enter sleep before any pending interrupt(s) */
; set Global Interrupt Enable
; store SREG value
; disable interrupts during timed sequence
; start EEPROM write
; restore SREG value (I-bit)
/* store SREG value */
/* restore SREG value (I-bit) */
Atmel ATmega16/32/64/M1/C1
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