ST72P262G1B6/XXX View Datasheet(PDF) - STMicroelectronics

Part Name

Description

Manufacturer

ST72P262G1B6/XXX

8-BIT MCU WITH FLASH OR ROM MEMORY, ADC, TWO 16-BIT TIMERS, I2C, SPI, SCI INTERFACES

STMicroelectronics 

ST72260G, ST72262G, ST72264G

POWER SAVING MODES (Cont’d)

8.3 WAIT MODE

WAIT mode places the MCU in a low power con-

sumption mode by stopping the CPU.

This power saving mode is selected by calling the

“WFI” ST7 software instruction.

All peripherals remain active. During WAIT mode,

the I [1:0] bits in the CC register are forced to ‘10b’,

to enable all interrupts. All other registers and

memory remain unchanged. The MCU remains in

WAIT mode until an interrupt or Reset occurs,

whereupon the Program Counter branches to the

starting address of the interrupt or Reset service

routine.

The MCU will remain in WAIT mode until a Reset

or an Interrupt occurs, causing it to wake up.

Refer to Figure 23.

Figure 23. WAIT Mode Flowchart

WFI INSTRUCTION

OSCILLATOR

PERIPHERALS

CPU

I[1:0] BITS

ON

ON

OFF

0

N

RESET

N

Y

INTERRUPT

Y

OSCILLATOR ON

PERIPHERALS OFF

CPU

ON

I[1:0] BITS

1

4096 CPU CLOCK CYCLE

DELAY

OSCILLATOR

PERIPHERALS

CPU

I[1:0] BITS

ON

ON

ON

XX 1)

FETCH RESET VECTOR

OR SERVICE INTERRUPT

Note:

1. Before servicing an interrupt, the CC register is

pushed on the stack. The I[1:0] bits in the CC reg-

ister are set during the interrupt routine and

cleared when the CC register is popped.

34/171

Share Link: