ATTINY861A-XU Atmel, ATTINY861A-XU Datasheet - Page 40

• Manufacturer Part Number: ATTINY861A-XU
• Description: Microcontrollers (MCU) 8K Flash;125B EEPROM 128B SRAM;16 IO Pins
• Manufacturer: Atmel

Specifications of ATTINY861A-XU

• Core: RISC
• Data Bus Width: 8 bit
• Program Memory Type: Flash
• Program Memory Size: 8 KB
• Data Ram Size: 512 B
• Interface Type: SPI
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 16
• Operating Supply Voltage: 1.8 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Package / Case: TSSOP-20
• Minimum Operating Temperature: - 40 C
• Lead Free Status / Rohs Status: Details

8.2
8.2.1
40
Reset Sources
ATtiny261A/461A/861A
Power-on Reset
The ATtiny261A/461A/861A has four sources of reset:
A Power-on Reset (POR) pulse is generated by an On-chip detection circuit. The detection level
is defined in
V
well as to detect a failure in supply voltage.
A Power-on Reset (POR) circuit ensures that the device is reset from Power-on. Reaching the
Power-on Reset threshold voltage invokes the delay counter, which determines how long the
device is kept in RESET after V
when V
Figure 8-2.
Figure 8-3.
CC
• Power-on Reset. The MCU is reset when the supply voltage is below the Power-on Reset
• External Reset. The MCU is reset when a low level is present on the RESET pin for longer
• Watchdog Reset. The MCU is reset when the Watchdog Timer period expires and the
• Brown-out Reset. The MCU is reset when the supply voltage V
threshold (V
than the minimum pulse length.
Watchdog is enabled.
Reset threshold (V
is below the detection level. The POR circuit can be used to trigger the Start-up Reset, as
INTERNAL
INTERNAL
TIME-OUT
TIME-OUT
CC
RESET
RESET
RESET
RESET
V
V
decreases below the detection level.
CC
CC
“System and Reset Characteristics” on page
MCU Start-up, RESET Tied to V
MCU Start-up, RESET Extended Externally
POT
).
BOT
) and the Brown-out Detector is enabled.
V
V
V
POT
POT
RST
CC
t
TOUT
rise. The RESET signal is activated again, without any delay,
CC
V
RST
t
TOUT
187. The POR is activated whenever
CC
is below the Brown-out
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