AT89C5131A-L Atmel Corporation, AT89C5131A-L Datasheet - Page 148

• Manufacturer Part Number: AT89C5131A-L
• Manufacturer: Atmel Corporation

Specifications of AT89C5131A-L

• Flash (kbytes): 32 Kbytes
• Max. Operating Frequency: 48 MHz
• Cpu: 8051-12C
• Max I/o Pins: 34
• Usb Transceiver: 1
• Usb Speed: Full Speed
• Usb Interface: Device
• Spi: 1
• Twi (i2c): 1
• Uart: 1
• Sram (kbytes): 1.25
• Eeprom (bytes): 1024
• Self Program Memory: API
• Operating Voltage (vcc): 3.0 to 3.6
• Timers: 4
• Isp: UART/USB
• Watchdog: Yes

Reset
Introduction
Reset Input
148
AT89C5131A-L
The reset sources are: Power Management, Hardware Watchdog, PCA Watchdog and
Reset input.
Figure 72. 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-up resistor allowing power-on reset
by simply connecting an external capacitor to V
and input characteristics are discussed in the Section “DC Characteristics” of the
AT89C5131A-L datasheet.
Figure 73. Reset Circuitry and Power-On Reset
RST
RST
Watchdog
Watchdog
Hardware
Monitor
Power
PCA
a. RST input circuitry
VCC
To internal reset
SS
as shown in Figure 73. Resistor value
b. Power-on Reset
Internal Reset
VSS
+
4338F–USB–08/07
RST