BK2535 datasheet(29/133 Pages) BEKEN

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BK2535 datasheet

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OSC32k_sel: System will select OSC32k (divided by OSC16M) clock when write 1

to this position. Interrupts and software can clear it. In this state, the system clock

changed to 32K OSC clock, so the power consumption will decrease evidently.

Please note that OSC32k clock is more accurate than RC 32k clock, but need

more power consumption.

IDLE: When set by software, system enter stop mode, and it can only be wake

up by enabled interrupt.(Clear it to 0 by hardware). In this state, the most of

clocks are shut down for power saving.

Note: set RC32k_sel and IDLE bit simultaneously can get the lowest power

consumption, and in this state, all the register settings are retained.

5.3.2.

Work State

5.3.2.1. Active Mode

Normally, the FLIP51 fetch the instruction from the program space and execute it

step by step at the selected clock source, we call the state as active mode.

5.3.2.2. Idle Mode

An instruction that sets the IDLE bit (PCON2.0) causes the FLIP51 to enter idle

mode when that instruction completes. In idle mode, CPU processing is

suspended; internal registers maintain their current data. However, unlike the

standard 8051, the clock is not disabled internally.

Activation of any enabled interrupt causes the hardware to clear the IDLE bit and

terminate idle mode.

In idle mode, the power consumption is decreased evidently.

5.3.2.3. Sleep Mode

An instruction that sets the IDLE bit (PCON2.0) causes the FLIP51 to enter idle

mode when that instruction completes. Also, you can decrease the power

consumption to a lower level thanks for the register PCON2.1. When setting the

state as sleep mode.

After reset, the system will enter normal mode running at 16MHz immediately.

Note: You should always clear PCON2.6 to 0 to save current when USB module

doesn’t need work at any time.

As showed above, the IDLE bit decide CPU run or not, the PCON2.1 bit decide

the system clock source. (16MHz or RC32KHz)

BK2535 Datasheet(PDF) 29 Page - Beken Corporation