ATtiny88 Automotive Atmel Corporation, ATtiny88 Automotive Datasheet - Page 42

• Manufacturer Part Number: ATtiny88 Automotive
• Manufacturer: Atmel Corporation

Specifications of ATtiny88 Automotive

• Flash (kbytes): 8 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: 28
• Ext Interrupts: 28
• 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): 0.5
• Eeprom (bytes): 64
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: Yes
• Temp. Range (deg C): -40 to 125
• 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: 2
• 32khz Rtc: No
• Calibrated Rc Oscillator: Yes

8.2.2
8.2.3
42
ATtiny88 Automotive
External Reset
Brown-out Detection
An External Reset is generated by a low level on the RESET pin. Reset pulses longer than the
minimum pulse width (see
running. Shorter pulses are not guaranteed to generate a reset. When the applied signal
reaches the Reset Threshold Voltage – V
MCU after the Time-out period – t
RSTDISBL fuse, see
Figure 8-4.
ATtiny88 has an On-chip Brown-out Detection (BOD) circuit for monitoring the V
operation by comparing it to a fixed trigger level. The trigger level for the BOD can be selected
by the BODLEVEL Fuses. The trigger level has a hysteresis to ensure spike free Brown-out
Detection. The hysteresis on the detection level should be interpreted as V
and V
trigger level (V
increases above the trigger level (V
the Time-out period t
The BOD circuit will only detect a drop in V
ger than t
Figure 8-5.
BOT-
BOD
= V
CC
given in
BOT
External Reset During Operation
Brown-out Reset During Operation
INTERNAL
TIME-OUT
BOT-
RESET
RESET
- V
V
in
HYST
CC
TOUT
Table 20-4 on page
“System and Reset Characterizations” on page
Figure
/2. When the BOD is enabled, and V
has expired.
Table 21-4 on page
8-5), the Brown-out Reset is immediately activated. When V
TOUT
BOT+
V
– has expired. The External Reset can be disabled by the
BOT-
in
RST
192.
CC
Figure
– on its positive edge, the delay counter starts the
if the voltage stays below the trigger level for lon-
211) will generate a reset, even if the clock is not
8-5), the delay counter starts the MCU after
CC
V
t
TOUT
BOT+
decreases to a value below the
211.
BOT+
= V
CC
9157B–AVR–01/10
BOT
level during
+ V
HYST
CC
/2