AT90S2313-4PI Atmel, AT90S2313-4PI Datasheet - Page 20

• Manufacturer Part Number: AT90S2313-4PI
• Description: IC MCU 2K 4MHZ UART LV IT 20DIP
• Manufacturer: Atmel
• Series: AVR® 90Sr

Specifications of AT90S2313-4PI

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 4MHz
• Connectivity: SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 15
• Program Memory Size: 2KB (1K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 128 x 8
• Ram Size: 128 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 6 V
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 20-DIP (0.300", 7.62mm)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Data Converters: -

Power-on Reset
20
AT90S2313
Table 4. Number of Watchdog Oscillator Cycles
A Power-on Reset (POR) circuit ensures that the device is reset from Power-on. As
shown in Figure 23, an internal timer is clocked from the Watchdog Timer. This timer
prevents the MCU from starting until after a certain period after V
Power-on Threshold voltage (V
can be programmed to give a shorter start-up time if a ceramic resonator or any other
fast-start Oscillator is used to clock the MCU.
If the built-in start-up delay is sufficient, RESET can be connected to V
an external pull-up resistor. By holding the RESET pin low for a period after V
been applied, the Power-on Reset period can be extended. Refer to Figure 25 for a tim-
ing example of this.
Figure 24. MCU Start-up, RESET Tied to V
Figure 25. MCU Start-up, RESET Controlled Externally
INTERNAL
TIME-OUT
INTERNAL
TIME-OUT
FSTRT
Programmed
Unprogrammed
RESET
RESET
RESET
RESET
VCC
VCC
V
V
V
Time-out at V
0.28 ms
16.0 ms
POT
RST
POT
t
TOUT
POT
) (see Figure 24). The FSTRT Fuse bit in the Flash
CC
= 5V
V
RST
CC
.
t
TOUT
Number of WDT Cycles
256
16K
CC
has reached the
CC
directly or via
0839I–AVR–06/02
CC
has