W741E20X Datasheet, PDF (25/84 Pages) Winbond – 4-BIT FLASH MICROCONTROLLER

Preliminary W741E20X
SEF 1 = 1 Device will exit stop mode when falling edge signal is applied to pin RC.1
SEF 2 = 1 Device will exit stop mode when falling edge signal is applied to pin RC.2
SEF 3 = 1 Device will exit stop mode when falling edge signal is applied to pin RC.3
Hold Mode Operation
In hold mode, all operations of the µC cease, except for the operation of the oscillator and timer. The
µC enters hold mode when the HOLD instruction is executed. The hold mode can be released in one
of five ways: by the action of timer 0, timer 1, the divider, the INT pin, the RC port. Before the device
enters the hold mode, the HEF, PEF, and IEF flags must be set to define the hold mode release
conditions. For more details, refer to the instruction-set table and the following flow chart.
Divider 0, /INT, Timer 0,
Timer 1, Serial I/O and
signal Change at RC Port
Yes
Interrupt
No
Enable?
Yes
IEF
No
Flag Set?
Yes
Reset EVF Flag
Execute
Interrupt Service Routine
(Note)
No
In
HOLD
Mode?
HEF
Flag Set?
No
Interrupt
No
Enable?
Yes
IEF
No
Flag Set?
Yes
Reset EVF Flag
Execute
Interrupt Service Routine
Yes
(Note)
Disable interrupt
Disable interrupt
HOLD
Note: The bit of EVF corresponding to the interrupt signal will be reset.
PC <- (PC+1)
Figure 14. Hold Mode and Interrupt Operation Flow Chart
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Publication Release Date: March 1998
Revision A1