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HOW TO MINIMIZE THE ST7 POWER CONSUMPTION

7 APPENDIX B: ST7FLITE0 STANDARD EXAMPLES

This section provides examples of how to minimise the consumption in a particular ST7 appli-

cation for device ST7FLITE09.( Use ST7LITE0 datasheet for a reference)

7.1 EXAMPLE 1: STATIC MEASUREMENT

This example provides a static method of measuring the current consumed by the microcon-

troller in different modes and without any I/O activity. The measurement is done using the fol-

lowing configuration.

7.1.1 Measurement Configuration

– All ports have been set as Push-Pull Outputs at low level.

– All other peripherals are in reset configuration.

– After this, MCU is put into different modes by calling different instructions and by setting

some bits (in the MCCSR & ATCSR registers).

– In Option Byte, PLL is disabled, Internal RC Oscillator is OFF, LVD is OFF & No Reset when

Halt is selected.

Figure 4. Hardware Setup

7.1.2 Consumption

The consumption mainly depends on the mode selected, CPU frequency & Supply voltage.

mA

ST7LITE0