ATtiny2313A Atmel Corporation, ATtiny2313A Datasheet - Page 42

• Manufacturer Part Number: ATtiny2313A
• Manufacturer: Atmel Corporation

Specifications of ATtiny2313A

• Flash (kbytes): 2 Kbytes
• Pin Count: 20
• Max. Operating Frequency: 20 MHz
• Cpu: 8-bit AVR
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 18
• Ext Interrupts: 18
• Usb Speed: No
• Usb Interface: No
• Spi: 2
• Twi (i2c): 1
• Uart: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Speed (ksps): 15
• Analog Comparators: 1
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 0.12
• Eeprom (bytes): 128
• 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: 4
• Input Capture Channels: 1
• Pwm Channels: 4
• 32khz Rtc: No
• Calibrated Rc Oscillator: Yes

8.2.4
8.3
8.3.1
8.4
42
Internal Voltage Reference
Watchdog Timer
ATtiny2313A/4313
Watchdog Reset
Voltage Reference Enable Signals and Start-up Time
When the Watchdog times out, it will generate a short reset pulse of one CK cycle duration. On
the falling edge of this pulse, the delay timer starts counting the Time-out period t
“Interrupts” on page 48
Figure 8-6.
ATtiny2313A/4313 features an internal bandgap reference. This reference is used for Brown-out
Detection, and it can be used as an input to the Analog Comparator. The bandgap voltage varies
with supply voltage and temperature.
The voltage reference has a start-up time that may influence the way it should be used. The
start-up time is given in
reference is not always turned on. The reference is on during the following situations:
Thus, when the BOD is not enabled, after setting the ACBG bit, the user must always allow the
reference to start up before the output from the Analog Comparator. To reduce power consump-
tion in Power-down mode, the user can avoid the three conditions above to ensure that the
reference is turned off before entering Power-down mode.
The Watchdog Timer is clocked from an On-chip Oscillator which runs at 128 kHz. By controlling
the Watchdog Timer prescaler, the Watchdog Reset interval can be adjusted as shown in
8-3 on page
Watchdog Timer is also reset when it is disabled and when a Chip Reset occurs. Ten different
clock cycle periods can be selected to determine the reset period. If the reset period expires
without another Watchdog Reset, the ATtiny2313A/4313 resets and executes from the Reset
Vector. For timing details on the Watchdog Reset, refer to
1. When the BOD is enabled (by programming the BODLEVEL [2..0] Fuse).
2. When the internal reference is connected to the Analog Comparator (by setting the
ACBG bit in ACSR).
CC
47. The WDR – Watchdog Reset – instruction resets the Watchdog Timer. The
Watchdog Reset During Operation
for details on operation of the Watchdog Timer.
“System and Reset Characteristics” on page
CK
Table 8-3 on page
201. To save power, the
47.
8246B–AVR–09/11
TOUT
Table
. See