AT89C51AC2-RLTUM Atmel, AT89C51AC2-RLTUM Datasheet - Page 21

• Manufacturer Part Number: AT89C51AC2-RLTUM
• Description: IC 8051 MCU FLASH 32K 44VQFP
• Manufacturer: Atmel
• Series: 89Cr

Specifications of AT89C51AC2-RLTUM

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 40MHz
• Connectivity: UART/USART
• Peripherals: POR, PWM, WDT
• Number Of I /o: 34
• Program Memory Size: 32KB (32K x 8)
• Program Memory Type: FLASH
• Eeprom Size: 2K x 8
• Ram Size: 1.25K x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-TQFP, 44-VQFP
• Processor Series: AT89x
• Core: 8051
• Data Bus Width: 8 bit
• Data Ram Size: 1280 B
• Interface Type: UART
• Maximum Clock Frequency: 40 MHz
• Number Of Programmable I/os: 34
• Number Of Timers: 3
• Operating Supply Voltage: 3 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: PK51, CA51, A51, ULINK2
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit, 8 Channel
• For Use With: AT89OCD-01 - USB EMULATOR FOR AT8XC51 MCU
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Figure 9. Power-down Exit Waveform Using INT1:0#
4127H–8051–02/08
INT1:0#
OSC
Active phase
2. Generate a reset.
Notes:
Table 14. Pin Conditions in Special Operating Modes
Down(inter
nal code)
(external
(external
(internal
Power-
Power-
Mode
Reset
code)
code)
Down
code)
–
Idle
Idle
1. During the time that execution resumes, the internal RAM cannot be accessed; how-
2. Exit from power-down by reset redefines all the SFRs, but does not affect the internal
A logic high on the RST pin clears PD bit in PCON register directly and
asynchronously. This starts the oscillator and restores the clock to the CPU
and peripherals. Program execution momentarily resumes with the
instruction immediately following the instruction that activated Power-down
mode and may continue for a number of clock cycles before the internal
reset algorithm takes control. Reset initializes the T89C51CC02 and vectors
the CPU to address 0000h.
Power-down phase
ever, it is possible for the Port pins to be accessed. To avoid unexpected outputs at
the Port pins, the instruction immediately following the instruction that activated the
Power-down mode should not write to a Port pin or to the external RAM.
RAM content.
Floating
Floating
Floating
Port 0
Data
Data
Port 1
Data
Data
Data
Data
High
Oscillator restart phase
Port 2
High
Data
Data
Data
Data
Port 3
High
Data
Data
Data
Data
Port 4
High
Data
Data
Data
Data
Active phase
A/T89C51AC2
ALE
High
High
High
Low
Low
PSEN#
High
High
High
Low
Low
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