ATMEGA8535L-8MU Atmel, ATMEGA8535L-8MU Datasheet - Page 36

• Manufacturer Part Number: ATMEGA8535L-8MU
• Description: IC AVR MCU 8K 8MHZ 3V 44-QFN
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA8535L-8MU

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 8MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 32
• Program Memory Size: 8KB (4K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 512 x 8
• Ram Size: 512 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-VQFN Exposed Pad
• Processor Series: ATMEGA8x
• Core: AVR8
• Data Bus Width: 8 bit
• Data Ram Size: 512 B
• Interface Type: SPI, TWI, UART
• Maximum Clock Frequency: 8 MHz
• Number Of Programmable I/os: 32
• Number Of Timers: 3
• Operating Supply Voltage: 2.7 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: EWAVR, EWAVR-BL
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit, 8 Channel
• Package: 44MLF EP
• Device Core: AVR
• Family Name: ATmega
• Maximum Speed: 8 MHz
• For Use With: ATSTK600-DIP40 - STK600 SOCKET/ADAPTER 40-PDIP770-1007 - ISP 4PORT ATMEL AVR MCU SPI/JTAGATAVRISP2 - PROGRAMMER AVR IN SYSTEMATSTK500 - PROGRAMMER AVR STARTER KIT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

System Control and
Reset
Resetting the AVR
Reset Sources
36
ATmega8535(L)
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 an
RJMP 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 15 shows the reset logic. Table 15 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 25.
The ATmega8535 has four 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
POT
).
BOT
) and the Brown-out Detector is enabled.
CC
is below the
2502K–AVR–10/06