AT83C5134 Atmel Corporation, AT83C5134 Datasheet - Page 131

• Manufacturer Part Number: AT83C5134
• Manufacturer: Atmel Corporation

Specifications of AT83C5134

• Max. Operating Frequency: 32 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): 512
• Operating Voltage (vcc): 2.7 to 3.6
• Timers: 4
• Mask Rom (kbytes): 8
• Watchdog: Yes

22. Reset
22.1
22.2
22.3
7683C–USB–11/07
Introduction
Reset Input
Reset Output
The reset sources are: Power Management, Hardware Watchdog, PCA Watchdog and Reset
input.
Figure 22-1. Reset schematic
The Reset input can be used to force a reset pulse longer than the internal reset controlled by
the Power Monitor. RST input has a pull-up resistor allowing power-on reset by simply connect-
ing an external capacitor to V
characteristics are discussed in the Section “DC Characteristics” of the AT83C5134/35/36
datasheet.
Figure 22-2. Reset Circuitry and Power-On Reset
As detailed in Section “Hardware Watchdog Timer”, page 138, the WDT generates a 96-clock
period pulse on the RST pin. In order to properly propagate this pulse to the rest of the applica-
tion in case of external capacitor or power-supply supervisor circuit, a 1 kΩ resistor must be
added as shown Figure 22-3.
RST
RST
Watchdog
Watchdog
Hardware
Monitor
Power
PCA
a. RST input circuitry
VCC
S S
as shown in Figure 22-2. Resistor value and input
To internal reset
AT83C5134/35/36
b. Power-on Reset
Internal Reset
VSS
+
RST
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