ST7-STICK45 STMICROELECTRONICS [STMicroelectronics], ST7-STICK45 Datasheet - Page 41

• Manufacturer Part Number: ST7-STICK45
• Description: 8-bit microcontroller with single voltage Flash memory, data EEPROM, ADC, timers, SPI
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

POWER SAVING MODES (Cont’d)
9.4.2.1 HALT Mode Recommendations
– Make sure that an external event is available to
– When using an external interrupt to wake up the
– For the same reason, reinitialize the level sensi-
wake up the microcontroller from Halt mode.
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 ex-
ternal interference or by an unforeseen logical
condition.
tiveness of each external interrupt as a precau-
tionary measure.
– The opcode for the HALT instruction is 0x8E. To
– As the HALT instruction clears the I bit in the CC
avoid an unexpected HALT instruction due to a
program counter failure, it is advised to clear all
occurrences of the data value 0x8E from memo-
ry. For example, avoid defining a constant in
ROM with the value 0x8E.
register to allow interrupts, the user may choose
to clear all pending interrupt bits before execut-
ing 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).
ST7LITE0xY0, ST7LITESxY0
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