Peripheral Simulation

For Atmel AT89C5131 — Power save modes (Idle & Power down)

Simulation support for this peripheral or feature is comprised of:

• Accurate simulation of special on-chip features.
• Example code which helps you get started quickly.

These simulation capabilities are described below.

Idle and Power Down Modes

The MCU supports two software selectable power saving modes. The Idle Mode stops the CPU while allowing the RAM, timer/counters, serial port and interrupt system to continue functioning. The Power-down Mode saves the RAM contents but freezes the oscillator disabling all other chip functions until the next hardware reset.

Idle Mode Example Program

The Keil Debugger fully simulates the effects of Idle Mode. When your target program initiates Idle Mode program execution stops until the next interrupt is triggered. The following example code shows how to enter Idle Mode.

while (1)          // Repeat Forever
  {
  PCON |= 0x01;    // Enter IDLE Mode
  count++;         // Interrupt Wakes-up MCU
  }

Power Down Mode Example Program

The Keil Debugger fully simulates the effects of Power Down Mode. When your target program initiates Power Down Mode program execution stops until the next external interrupt is triggered or until the MCU is reset. The following example code shows how to enter Power Down Mode.

while (1)          // Repeat Forever
  {
  PCON |= 0x02;    // Enter Power Down Mode
  count++;         // External Interrupt or Reset Wakes-up MCU
  }