ATmega32C1 Automotive Atmel Corporation, ATmega32C1 Automotive Datasheet - Page 51

• Manufacturer Part Number: ATmega32C1 Automotive
• Manufacturer: Atmel Corporation

Specifications of ATmega32C1 Automotive

• Flash (kbytes): 32 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): 2
• Eeprom (bytes): 1024
• 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

7.3
7.3.1
7.3.2
7647G–AVR–09/11
Internal Voltage Reference
Voltage Reference Enable Signals and Start-up Time
Voltage Reference Characteristics
• Bit 1 – EXTRF: External Reset Flag
This bit is set if an External Reset occurs. The bit is reset by a Power-on Reset, or by writing a
logic zero to the flag.
• Bit 0 – PORF: Power-on Reset Flag
This bit is set if a Power-on Reset occurs. The bit is reset only by writing a logic zero to the
flag.
To make use of the Reset flags to identify a reset condition, the user should read and then
reset the MCUSR as early as possible in the program. If the register is cleared before another
reset occurs, the source of the reset can be found by examining the reset flags.
ATmega16/32/64/M1/C1 features an internal bandgap reference. This reference is used for
Brown-out DetectionDetection, and it can be used as an input to the Analog Comparators or
the ADC. The V
from the internal bandgap reference.
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 on during the following situations:
1. When the BOD is enabled (by programming the BODLEVEL [2..0] Fuse).
2. When the bandgap reference is connected to the Analog Comparator (by setting the
3. When the ADC is enabled.
4. When the DAC is enabled.
Thus, when the BOD is not enabled, after setting the ACBG bit or enabling the ADC or the
DAC, the user must always allow the reference to start up before the output from the Analog
Comparator or ADC or DAC is used. To reduce power consumption 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.
Table 7-4.
Note:
Symbol
V
ACBG bit in ACSR).
t
I
BG
BG
BG
1. Values are guidelines only.
Parameter
Bandgap reference voltage
Bandgap reference start-up time
Bandgap reference current
consumption
Internal Voltage Reference Characteristics
REF
2.56V reference to the ADC, DAC or Analog Comparators is generated
Table
7-4. To save power, the reference is not always turned on. The
Atmel ATmega16/32/64/M1/C1
Condition
(1)
Min.
Typ.
1.1
40
15
Max.
Units
µA
µs
V
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