ATtiny461A Atmel Corporation, ATtiny461A Datasheet - Page 80

• Manufacturer Part Number: ATtiny461A
• Manufacturer: Atmel Corporation

Specifications of ATtiny461A

• Flash (kbytes): 4 Kbytes
• Pin Count: 20
• Max. Operating Frequency: 20 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 8
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 16
• Ext Interrupts: 16
• Usb Speed: No
• Usb Interface: No
• Spi: 1
• Twi (i2c): 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 11
• Adc Resolution (bits): 10
• Adc Speed (ksps): 15
• Analog Comparators: 1
• Resistive Touch Screen: No
• Temp. Sensor: Yes
• Crypto Engine: No
• Sram (kbytes): 0.25
• Eeprom (bytes): 256
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: Yes
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 1.8 to 5.5
• Operating Voltage (vcc): 1.8 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 2
• Output Compare Channels: 6
• Input Capture Channels: 1
• Pwm Channels: 6
• 32khz Rtc: No
• Calibrated Rc Oscillator: Yes

80
ATtiny261A/461A/861A
The following code examples show how to access the 16-bit timer registers assuming that no
interrupts updates the temporary register. The same principle can be used directly for accessing
the OCR0A/B registers.
Note:
The assembly code example returns the TCNT0H/L value in the r17:r16 register pair.
It is important to notice that accessing 16-bit registers are atomic operations. If an interrupt
occurs between the two instructions accessing the 16-bit register, and the interrupt code
updates the temporary register by accessing the same or any other of the 16-bit timer registers,
then the result of the access outside the interrupt will be corrupted. Therefore, when both the
main code and the interrupt code update the temporary register, the main code must disable the
interrupts during the 16-bit access.
Assembly Code Example
C Code Example
unsigned int i;
...
/* Set TCNT0 to 0x01FF */
TCNT0H = 0x01;
TCNT0L = 0xff;
/* Read TCNT0 into i */
i = TCNT0L;
i |= ((unsigned int)TCNT0H << 8);
...
...
; Set TCNT0 to 0x01FF
ldi r17,0x01
ldi r16,0xFF
out TCNT0H,r17
out TCNT0L,r16
; Read TCNT0 into r17:r16
in r16,TCNT0L
in r17,TCNT0H
...
See
“Code Examples” on page
6.
8197C–AVR–05/11