Unlock Microcontroller AT89C5132 Code

We can Unlock Microcontroller AT89C5132 Code, please view the Microcontroller AT89C5132 features for your reference:

2 power reduction modes are implemented in the AT89C5132: the Idle mode and the Power- down mode. These modes are detailed in the following sections. In addition to these power reduction modes, the clocks of the core and peripherals can be dynamically divided by 2 using the X2 mode detailed in Section “X2 Feature” when Unlock Microcontroller.

In order to start-up (cold reset) or to restart (warm reset) properly the microcontroller, an high level has to be applied on the RST pin. A bad level leads to a wrong initialization of the internal registers like SFRs, Program Counter… and to unpredictable behavior of the microcontroller if Unlock Microcontroller.

A proper device reset initializes the AT89C5132 and vectors the CPU to address 0000h. RST input has a pull-down resistor allowing power-on reset by simply connecting an external capacitor to VDD as shown in Figure 11-1. A warm reset can be applied either directly on the RST pin or indirectly by an internal reset source such as the watchdog timer. Resistor value and input characteristics are discussed in the Section “DC Characteristics” of the AT89C5132 datasheet before Unlock Microcontroller.

An example of bad initialization situation may occur in an instance where the bit ENBOOT in AUXR1 register is initialized from the hardware bit BLJB upon reset. Since this bit allows mapping of the bootloader in the code area, a reset failure can be critical after Unlock Microcontroller.

If one wants the ENBOOT cleared in order to unmap the boot from the code area (yet due to a bad reset) the bit ENBOOT in SFRs may be set. If the value of Program Counter is accidently in the range of the boot memory addresses then a Flash access (write or erase) may corrupt the Flash on-chip memory when Unlock Microcontroller.

It is recommended to use an external reset circuitry featuring power supply monitoring to prevent system malfunction during periods of insufficient power supply voltage (power supply failure, power supply switched off). Idle mode is a power reduction mode that reduces the power consumption. In this mode, program execution halts if Unlock Microcontroller.

Idle mode freezes the clock to the CPU at known states while the peripherals continue to be clocked (refer to Section “Oscillator”, page 12). The CPU status before entering Idle mode is preserved, i.e., the program counter and program status word register retain their data for the duration of Idle mode. The contents of the SFRs and RAM are also retained before Unlock Microcontroller.

There are 2 ways to exit Idle mode:

Generate an enabled interrupt.

Hardware clears IDL bit in PCON register which restores the clock to the CPU.

Execution resumes with the interrupt service routine. Upon completion of the interrupt service routine, program execution resumes with the instruction immediately following the instruction that activated Idle mode. The general-purpose flags (GF1 and GF0 in PCON register) may be used to indicate whether an interrupt occurred during normal operation or during Idle mode. When Idle mode is exited by an interrupt, the interrupt service routine may examine GF1 and GF0 when Unlock Microcontroller.

Generate a reset.

A logic high on the RST pin clears IDL bit in PCON register directly and asynchronously. This restores the clock to the CPU. Program execution momentarily resumes with the instruction immediately following the instruction that activated the Idle mode and may continue for a number of clock cycles before the internal reset algorithm takes control before Unlock Microcontroller.

Reset initializes the AT89C5132 and vectors the CPU to address C:0000h. The Power-down mode places the AT89C5132 in a very low power state. Power-down mode stops the oscillator and freezes all clocks at known states (refer to the Section “Oscillator”, page 12) after Unlock Microcontroller.

The CPU status prior to entering Power-down mode is preserved, i.e., the program counter, program status word register retain their data for the duration of Power-down mode. In addition, the SFRs and RAM contents are preserved. To enter Power-down mode, set PD bit in PCON register. The AT89C5132 enters the Power-down mode upon execution of the instruction that sets PD bit. The instruction that sets PD bit is the last instruction executed if Unlock Microcontroller.


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