AT90LS2333-4AI Atmel, AT90LS2333-4AI Datasheet - Page 19

• Manufacturer Part Number: AT90LS2333-4AI
• Description: IC MCU 2K 4MHZ A/D LV IT 32TQFP
• Manufacturer: Atmel
• Series: AVR® 90LSr

Specifications of AT90LS2333-4AI

• 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: 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): 2.7 V ~ 6 V
• Data Converters: A/D 6x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 32-TQFP, 32-VQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

Reset Sources
The AT90S2333/4433 has four sources of reset:
• Power-On Reset. The MCU is reset when the supply voltage is below the power-on reset threshold (V
• External Reset. The MCU is reset when a low level is present on the RESET pin for more than 50 ns.
• Watchdog Reset. The MCU is reset when the Watchdog timer period expires and the Watchdog is enabled.
• Brown-Out Reset. The MCU is reset when the supply voltage V
During reset, all I/O registers are then set to their initial values, and the program starts execution from address $000. The
instruction placed in address $000 must be an RJMP - relative jump - instruction to the reset handling routine. If the pro-
gram never enables an interrupt source, the interrupt vectors are not used, and regular program code can be placed at
these locations. The circuit diagram in Figure 24 shows the reset logic. Table 4 and Table 5 define the timing and electrical
parameters of the reset circuitry.
Figure 24. Reset Logic
Table 4. Reset Characteristics (V
Note:
Symbol
V
V
V
$00e
$00f
$010
POT
RST
BOT
…
The Power-On Reset will not work unless the supply voltage has been below Vpot (falling).
Parameter
Power-On Reset Threshold Voltage,
rising
Power-On Reset Threshold Voltage,
falling
Brown-Out Reset Threshold Voltage
RESET Pin Threshold Voltage
BODLEVEL
BODEN
MAIN:
…
CC
= 5.0V)
ldi
out
<instr>
Reset Circuit
Brown-Out
…
r16,low(RAMEND); Main program start
SP,r16;
…
xxx
2.6 (BODLEVEL = 1)
3.8 (BODLEVEL = 0)
CK
Register (MCUSR)
AT90S/LS2333 and AT90S/LS4433
MCU Status
DATA BUS
CKSEL[2:0]
Min
1.0
0.4
Delay Counters
;
CC
falls below a certain voltage.
2.7 (BODLEVEL = 1)
4.0 (BODLEVEL = 0)
Full
0.6V
Typ
1.4
0.6
CC
2.8 (BODLEVEL = 1)
4.2 (BODLEVEL = 0)
Max
1.8
0.8
POT
).
Units
V
V
V
V
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