ATtiny20 Atmel Corporation, ATtiny20 Datasheet - Page 110

• Manufacturer Part Number: ATtiny20
• Manufacturer: Atmel Corporation

Specifications of ATtiny20

• Flash (kbytes): 2 Kbytes
• Pin Count: 14
• Max. Operating Frequency: 12 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 5
• Hardware Qtouch Acquisition: Yes
• Max I/o Pins: 12
• Ext Interrupts: 12
• Usb Speed: No
• Usb Interface: No
• Spi: 1
• Twi (i2c): 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: Yes
• Crypto Engine: No
• Sram (kbytes): 0.12
• Self Program Memory: NO
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• 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: 4
• Input Capture Channels: 1
• Pwm Channels: 3
• 32khz Rtc: No
• Calibrated Rc Oscillator: Yes

14.2.2
110
ATtiny20
ACSRB – Analog Comparator Control and Status Register B
• Bit 4 – ACI: Analog Comparator Interrupt Flag
This bit is set by hardware when a comparator output event triggers the interrupt mode defined
by ACIS1 and ACIS0. The Analog Comparator interrupt routine is executed if the ACIE bit is set
and the I-bit in SREG is set. ACI is cleared by hardware when executing the corresponding inter-
rupt handling vector. Alternatively, ACI is cleared by writing a logic one to the flag.
• Bit 3 – ACIE: Analog Comparator Interrupt Enable
When the ACIE bit is written logic one and the I-bit in the Status Register is set, the Analog Com-
parator interrupt is activated. When written logic zero, the interrupt is disabled.
• Bit 2 – ACIC: Analog Comparator Input Capture Enable
When written logic one, this bit enables the input capture function in Timer/Counter1 to be trig-
gered by the Analog Comparator. The comparator output is then directly connected to the input
capture front-end logic, making the comparator utilize the noise canceler and edge select fea-
tures of the Timer/Counter1 Input Capture interrupt.
When written logic zero, no connection between the Analog Comparator and the input capture
function exists. To make the comparator trigger the Timer/Counter1 Input Capture inter-rupt, the
ICIE1 bit in the Timer Interrupt Mask Register (TIMSK) must be set.
• Bits 1:0 – ACIS[1:0]: Analog Comparator Interrupt Mode Select
These bits determine which comparator events that trigger the Analog Comparator interrupt. The
different settings are shown in
Table 14-2.
When changing the ACIS1/ACIS0 bits, the Analog Comparator Interrupt must be disabled by
clearing its Interrupt Enable bit in the ACSR Register. Otherwise an interrupt can occur when the
bits are changed.
• Bit 7 – HSEL: Hysteresis Select
When this bit is written logic one, the hysteresis of the analog comparator is enabled. The level
of hysteresis is selected by the HLEV bit.
Bit
0x13
Read/Write
Initial Value
ACIS1
0
0
1
1
ACIS1/ACIS0 Settings
HSEL
R/W
7
0
ACIS0
0
1
0
1
HLEV
R/W
6
0
Interrupt Mode
Comparator Interrupt on Output Toggle.
Reserved
Comparator Interrupt on Falling Output Edge.
Comparator Interrupt on Rising Output Edge.
Table
ACLP
R/W
5
0
14-2.
4
–
R
0
ACCE
R/W
3
0
ACME
R/W
2
0
ACIRS1
R/W
1
0
ACIRS0
R/W
0
0
8235B–AVR–04/11
ACSRB