SAB80515 Datasheet, PDF (98/270 Pages) Siemens Semiconductor Group – 8-Bit Single-Chip Microcontroller Family

On-Chip Peripheral Components
Figure 7-42
Capture with Registers CC1 to CC3
7.6 Power Saving Modes
For significantly reducing power consumption, the SAB 80(C)515/80(C)535 provides two Power
Saving Modes:
– The Power-Down Mode
Operation of the component stops completely, the oscillator is turned off. Only the internal
RAM is supplied with a very low standby current.
– The Idle Mode (SAB 80C515/80C535 only)
The CPU is gated off from the oscillator. All peripherals are further supplied by the oscillator
clock and are able to do their jobs.
These modes are described separatly for each component in the following sections.
There are numerous applications which require high system security and at the same time reliability
in electrically noisy environments. In such applications unintentional entering of the power saving
modes must be absolutely avoided. A power saving mode would reduce the controller’s perfomance
(in case of idle mode) or even stop each operation (in case of power-down mode). This situation
might be fatal for the system. Such critical applications often use the watchdog timer to prevent the
system from program upsets. Then accidental entering of the power saving modes would even stop
the watchdog timer and would circumvent the task of system reliability.
The SAB 80C515/80C535 provides software and hardware protection against accidental entering
as described above (see chapter 7.6.2).
Semiconductor Group
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