C517A_99 Datasheet, PDF (209/218 Pages) Siemens Semiconductor Group – 8-Bit CMOS Microcontroller

Power Saving Modes
C517A
9.9 Hardware Power Down Reset Timing
The following figures show the timing diagrams for entering (figure 9-1) and leaving (figure 9-2) the
hardware power down mode. If there is only a short signal at pin HWPD (i.e. HWPD is sampled
active only once), then a complete internal reset is executed. Afterwards, the normal program
execution starts again (figure 9-3).
Note: Delay time caused by internal logic is not included.
The RESET pin overrides the hardware power down function, i.e. if reset gets active during
hardware power down it is terminated and the device performs the normal reset function. Thus, pin
RESET has to be inactive during hardware power down mode.
Semiconductor Group
9-11