ATMEGA162-16PC Atmel, ATMEGA162-16PC Datasheet - Page 45

• Manufacturer Part Number: ATMEGA162-16PC
• Description: IC MCU AVR 16K 5V 16MHZ 40-DIP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA162-16PC

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: EBI/EMI, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 35
• Program Memory Size: 16KB (8K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 512 x 8
• Ram Size: 1K x 8
• Voltage - Supply (vcc/vdd): 4.5 V ~ 5.5 V
• Oscillator Type: Internal
• Operating Temperature: 0°C ~ 70°C
• Package / Case: 40-DIP (0.600", 15.24mm)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Data Converters: -

System Control and
Reset
Resetting the AVR
Reset Sources
2513C–AVR–09/02
During Reset, all I/O Registers are set to their initial values, and the program starts exe-
cution from the Reset Vector. The instruction placed at the Reset Vector must be a JMP
– Absolute Jump – instruction to the reset handling routine. If the program never
enables an interrupt source, the Interrupt Vectors are not used, and regular program
code can be placed at these locations. This is also the case if the Reset Vector is in the
Application section while the Interrupt Vectors are in the Boot section or vice versa. The
circuit diagram in Figure 21 shows the Reset Logic. Table 18 defines the electrical
parameters of the reset circuitry.
The I/O ports of the AVR are immediately reset to their initial state when a reset source
goes active. This does not require any clock source to be running.
After all reset sources have gone inactive, a delay counter is invoked, stretching the
Internal Reset. This allows the power to reach a stable level before normal operation
starts. The Time-out period of the delay counter is defined by the user through the
CKSEL Fuses. The different selections for the delay period are presented in “Clock
Sources” on page 34.
The ATmega162 has five sources of reset:
•
•
•
•
•
Power-on Reset. The MCU is reset when the supply voltage is below the Power-on
Reset threshold (V
External Reset. The MCU is reset when a low level is present on the RESET pin for
longer than the minimum pulse length.
Watchdog Reset. The MCU is reset when the Watchdog Timer period expires and
the Watchdog is enabled.
Brown-out Reset. The MCU is reset when the supply voltage V
Brown-out Reset threshold (V
device is guaranteed to operate at maximum frequency for the V
V
minimum V
JTAG AVR Reset. The MCU is reset as long as there is a logic one in the Reset
Register, one of the scan chains of the JTAG system. Refer to the section “IEEE
1149.1 (JTAG) Boundary-scan” on page 201 for details.
BOT
. V
BOT
must be set to the corresponding minimum voltage of the device (i.e.,
BOT
for ATmega162V is 1.8V).
POT
).
BOT
) and the Brown-out Detector is enabled. The
ATmega162(V/U/L)
CC
CC
is below the
voltage down to
45