sak-c868p-1rr Infineon Technologies Corporation, sak-c868p-1rr Datasheet - Page 228

• Manufacturer Part Number: sak-c868p-1rr
• Description: 8 - Bit Cmos Microcontroller
• Manufacturer: Infineon Technologies Corporation

8.5
In the software power down mode, the on-chip oscillator which operates with the XTAL
pins and the PLL are all stopped. Therefore, all functions of the microcontroller are
stopped and only the contents of the on-chip RAM, XRAM and the SFR's are maintained.
The port pins, which are controlled by their port latches, output the values that are held
by their SFR's. The port pins which serve the alternate output functions show the values
they had at the end of the last cycle of the instruction which initiated the power down
mode. ALE is held at logic level high unless it is disabled.
In the power down mode of operation, V
consumption. It must be ensured, however, that V
down mode is invoked, and that V
power down mode is terminated.
The software power down mode can be left either by an active reset signal or by a low
signal at one of the wake-up source pins. Using reset to leave power down mode puts
the microcontroller with its SFRs into the reset state. Using either the INT0 pin or the
RXD pin for power down mode exit starts the on-chip oscillator and the PLL and
maintains the state of the SFRs, which have been frozen when power down mode is
entered. Leaving power down mode should not be done before V
to its nominal operating level.
The software power down mode is entered by setting bit PDE (PCON.1).
Note: Before entering the power down mode, an A/D conversion in progress must be
8.5.1
If power down mode is exit via a hardware reset, the microcontroller with its SFRs is put
into the hardware reset state and the content of RAM and XRAM are not changed. The
reset signal that terminates the power down mode also restarts the on-chip oscillator and
the PLL. The reset operation should not be activated before V
operating level.
Figure 8-1
wake-up capability.
User’s Manual
stopped.
Software Power Down Mode
Exit from Software Power Down Mode
shows the behaviour when power down mode is left via the INT0 or the RXD
DDP
is restored to its normal operating level before the
8-6
DDP
can be reduced to minimize power
DDP
is not reduced before the power
DDP
is restored to its normal
Power Saving Modes
DDC
and V
DDP
V 1.0, 2003-01
is restored
C868