AT89C51ID2 Atmel Corporation, AT89C51ID2 Datasheet - Page 31

• Manufacturer Part Number: AT89C51ID2
• Manufacturer: Atmel Corporation

Specifications of AT89C51ID2

• Flash (kbytes): 64 Kbytes
• Max. Operating Frequency: 60 MHz
• Cpu: 8051-12C
• Max I/o Pins: 32
• Spi: 1
• Twi (i2c): 1
• Uart: 1
• Sram (kbytes): 2
• Eeprom (bytes): 2048
• Self Program Memory: API
• Operating Voltage (vcc): 2.7 to 5.5
• Timers: 4
• Isp: UART
• Watchdog: Yes

Reset
Introduction
Reset Input
4289C–8051–11/05
The reset sources are : Power Management, Hardware Watchdog, PCA Watchdog and
Reset input.
Figure 7. Reset schematic
The Reset input can be used to force a reset pulse longer than the internal reset con-
trolled by the Power Monitor. RST input has a pull-down resistor allowing power-on
reset by simply connecting an external capacitor to V
value and input characteristics are discussed in the Section “DC Characteristics” of the
AT89C51ID2 datasheet.
Figure 8. Reset Circuitry and Power-On Reset
RST
RST
Watchdog
Watchdog
Hardware
a. RST input circuitry
Monitor
VSS
Power
PCA
To internal reset
CC
as shown in Figure 8. Resistor
AT89C51ID2
b. Power-on Reset
Internal Reset
VDD
+
RST
31