Datasheet

C164CI/SI
C164CL/SL
Data Sheet 30 V2.0, 2001-05
Power Management
The C164CI provides several means to control the power it consumes either at a given
time or averaged over a certain timespan. Three mechanisms can be used (partly in
parallel):
• Power Saving Modes switch the C164CI into a special operating mode (control via
instructions).
Idle Mode stops the CPU while the peripherals can continue to operate.
Sleep Mode and Power Down Mode stop all clock signals and all operation (RTC may
optionally continue running). Sleep Mode can be terminated by external interrupt
signals.
• Clock Generation Management controls the distribution and the frequency of
internal and external clock signals (control via register SYSCON2).
Slow Down Mode lets the C164CI run at a CPU clock frequency of
f
OSC
/1 … 32 (half
for prescaler operation) which drastically reduces the consumed power. The PLL can
be optionally disabled while operating in Slow Down Mode.
External circuitry can be controlled via the programmable frequency output FOUT.
• Peripheral Management permits temporary disabling of peripheral modules (control
via register SYSCON3).
Each peripheral can separately be disabled/enabled. A group control option disables
a major part of the peripheral set by setting one single bit.
The on-chip RTC supports intermittend operation of the C164CI by generating cyclic
wakeup signals. This offers full performance to quickly react on action requests while the
intermittend sleep phases greatly reduce the average power consumption of the system.