P89V51RD2FA NXP Semiconductors, P89V51RD2FA Datasheet - Page 59

• Manufacturer Part Number: P89V51RD2FA
• Description: MCU 8-Bit 89V 80C51 CISC 64KB Flash 5V 44-Pin PLCC Tube
• Manufacturer: NXP Semiconductors

Specifications of P89V51RD2FA

• Program Memory Size: 64 KB
• Package: 44PLCC
• Device Core: 80C51
• Family Name: 89V
• Maximum Speed: 40 MHz
• Operating Supply Voltage: 5 V
• Data Bus Width: 8 Bit
• Number Of Programmable I/os: 32
• Interface Type: SPI/UART
• Number Of Timers: 3
• Ram Size: 1 KB
• Program Memory Type: Flash
• Operating Temperature: -40 to 85 °C
• Controller Family/series: 80C51
• No. Of I/o's: 32
• Ram Memory Size: 1KB
• Cpu Speed: 40MHz
• No. Of Timers: 4
• No. Of Pwm Channels: 5
• Digital Ic Case Style: LCC
• Core Size: 8 Bit
• Embedded Interface Type: UART
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

NXP Semiconductors
Table 56.
P89V51RB2_RC2_RD2_5
Product data sheet
Mode
Idle mode
Power-down
mode
Power-saving modes
6.12.2 Power-down mode
Initiated by
Software (Set IDL bit in
PCON) MOV PCON, #01H
Software (Set PD bit in
PCON) MOV PCON, #02H
The device exits Idle mode through either a system interrupt or a hardware reset. Exiting
Idle mode via system interrupt, the start of the interrupt clears the IDL bit and exits Idle
mode. After exit the Interrupt Service Routine, the interrupted program resumes execution
beginning at the instruction immediately following the instruction which invoked the Idle
mode. A hardware reset starts the device similar to a power-on reset.
The Power-down mode is entered by setting the PD bit in the PCON register. In the
Power-down mode, the clock is stopped and external interrupts are active for level
sensitive interrupts only. SRAM contents are retained during Power-down mode, the
minimum V
The device exits Power-down mode through either an enabled external level sensitive
interrupt or a hardware reset. The start of the interrupt clears the PD bit and exits
Power-down. Holding the external interrupt pin low restarts the oscillator, the signal must
hold low at least 1024 clock cycles before bringing back high to complete the exit. Upon
interrupt signal restored to logic V
resumes beginning at the instruction immediately following the instruction which invoked
Power-down mode. A hardware reset starts the device similar to power-on reset.
To exit properly out of Power-down mode, the reset or external interrupt should not be
executed before the V
V
stabilize (normally less than 10 ms).
DD
voltage long enough at its normal operating level for the oscillator to restart and
DD
level is 2.0 V.
State of MCU
CLK is running. Interrupts,
serial port and timers/counters
are active. Program Counter is
stopped. ALE and PSEN
signals at a HIGH level during
Idle. All registers remain
unchanged.
CLK is stopped. On-chip SRAM
and SFR data is maintained.
ALE and PSEN signals at a
LOW level during power -down.
External Interrupts are only
active for level sensitive
interrupts, if enabled.
Rev. 05 — 12 November 2009
DD
line is restored to its normal operating voltage. Be sure to hold
IH
, the interrupt service routine program execution
P89V51RB2/RC2/RD2
8-bit microcontrollers with 80C51 core
Exited by
Enabled interrupt or hardware reset. Start of
interrupt clears IDL bit and exits Idle mode,
after the ISR RETI instruction, program
resumes execution beginning at the
instruction following the one that invoked
Idle mode. A user could consider placing
two or three NOP instructions after the
instruction that invokes Idle mode to
eliminate any problems. A hardware reset
restarts the device similar to a power-on
reset.
Enabled external level sensitive interrupt or
hardware reset. Start of interrupt clears PD
bit and exits Power-down mode, after the
ISR RETI instruction program resumes
execution beginning at the instruction
following the one that invoked Power-down
mode. A user could consider placing two or
three NOP instructions after the instruction
that invokes Power-down mode to eliminate
any problems. A hardware reset restarts the
device similar to a power-on reset.
© NXP B.V. 2009. All rights reserved.
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