ST72324BJ2 datasheet(52/188 Pages) STMICROELECTRONICS

Part #	ST72324BJ2

Description	8-bit MCU, 3.8 to 5.5 V operating range with 8 to 32 Kbyte Flash/ROM, 10-bit ADC, 4 timers, SPI, SCI

PDF	188 Pages

Scroll/Zoom	100%

Manufacturer	STMICROELECTRONICS [STMicroelectronics]

Direct Link	http://www.st.com

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52 / 188 page

Power saving modes

ST72324B

52/188

Halt mode recommendations

●

Make sure that an external event is available to wake up the microcontroller from Halt

mode.

●

When using an external interrupt to wake up the microcontroller, reinitialize the

corresponding I/O as “Input Pull-up with Interrupt” before executing the HALT

instruction. The main reason for this is that the I/O may be wrongly configured due to

external interference or by an unforeseen logical condition.

●

For the same reason, reinitialize the sensitivity level of each external interrupt as a

precautionary measure.

●

The opcode for the HALT instruction is 0x8E. To avoid an unexpected HALT instruction

due to a program counter failure, it is advised to clear all occurrences of the data value

0x8E from memory. For example, avoid defining a constant in ROM with the value

0x8E.

●

As the HALT instruction clears the interrupt mask in the CC register to allow interrupts,

the user may choose to clear all pending interrupt bits before executing the HALT

instruction. This avoids entering other peripheral interrupt routines after executing the

external interrupt routine corresponding to the wake-up event (reset or external

interrupt).

ST72324BJ2 Datasheet(PDF) 52 Page - STMicroelectronics