AT90S2333-8AC Atmel, AT90S2333-8AC Datasheet - Page 22

• Manufacturer Part Number: AT90S2333-8AC
• Description: IC MCU 2K FLSH 8MHZ A/D 32TQFP
• Manufacturer: Atmel
• Series: AVR® 90Sr

Specifications of AT90S2333-8AC

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 8MHz
• Connectivity: SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 20
• 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): 4 V ~ 6 V
• Data Converters: A/D 6x10b
• Oscillator Type: Internal
• Operating Temperature: 0°C ~ 70°C
• Package / Case: 32-TQFP, 32-VQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

Figure 28. Brown-Out Reset During Operation
Watchdog Reset
When the Watchdog times out, it will generate a short reset pulse of 1 XTAL cycle duration. On the falling edge of this
pulse, the delay timer starts counting the Time-out period t
Watchdog.
Figure 29. Watchdog Reset During Operation
MCU Status Register - MCUSR
The MCU Status Register provides information on which reset source caused an MCU reset.
•
These bits are reserved bits in the AT90S2333 and always read as zero.
•
This bit is set if a watchdog reset occurs. The bit is cleared by a power-on reset, or by writing a logic zero to the flag.
•
This bit is set if a brown-out reset occurs. The bit is cleared by a power-on reset, or by writing a logic zero to the flag.
•
This bit is set if an external reset occurs. The bit is cleared by a power-on reset, or by writing a logic zero to the flag.
•
This bit is set if a power-on reset occurs. The bit is cleared only by writing a logic zero to the flag.
22
Bit
$34 ($54)
Read/Write
Initial value
Bits 7..4 - Res: Reserved Bits
Bit 3 - WDRF: Watchdog Reset Flag
Bit 2 - BORF: Brown-Out Reset Flag
Bit 1 - EXTRF: External Reset Flag
Bit 0 - PORF: Power-on Reset Flag
AT90S/LS2333 and AT90S/LS4433
R
7
0
-
R
6
0
-
INTERNAL
TIME-OUT
RESET
RESET
VCC
R
5
0
-
R
4
0
-
V
BOT-
WDRF
R/W
3
TOUT
BORF
. Refer to Page page 36 for details on operation of the
R/W
2
See bit description
V
t
EXTRF
TOUT
BOT+
R/W
1
PORF
R/W
0
MCUSR