SAF-C164SM Infineon Technologies, SAF-C164SM Datasheet - Page 413

• Manufacturer Part Number: SAF-C164SM
• Description: 16-Bit CMOS Microcontroller
• Manufacturer: Infineon Technologies

21.6
The system clock output (CLKOUT) can be replaced by the programmable frequency
output signal
can be adapted to the requirements of connected external circuitry. The programmability
extends power management to the system level as circuitry external to the C164CM can
be influenced. Peripherals, for instance, can run at a scalable frequency or can be
switched off temporarily.
This clock signal is generated via a reload counter, so the output frequency can be
selected in small steps. An optional toggle latch can provide a clock signal with a 50%
duty cycle.
Figure 21-6 Clock Output Signal Generation
Signal
• When
• When
Signal
if PCD is disabled,
independently from on-chip peripherals.
Note: Counter FOCNT is clocked with the CPU clock signal
Register FOCON provides control over the output signal generation (frequency,
waveform, activation) as well as all status information (counter value, FOTL).
User’s Manual
f
OUT
therefore, will also be influenced by the SDD operation.
f
f
OUT
has reached or is ‘0’.
OUT
f
f
FOEN
f
CPU
OUT
OUT
Programmable Frequency Output Signal
always provides complete output periods (see Signal Waveforms below):
is independent of the peripheral clock driver PCD. While CLKOUT will stop
f
is started (FOEN --> ‘1’) FOCNT is loaded from FORV
is stopped (FOEN --> ‘0’) FOCNT is stopped when
OUT
. This signal can be controlled via software (unlike CLKOUT), and so
f
OUT
Ctrl.
will continue to toggle. Thus, external circuitry may be controlled
FOCNT
FORV
21-17
FOTL
f
CPU
FOSS
MUX
(see
Power Management
C164CM/C164SM
Figure
MCA04480
Derivatives
f
V1.0, 2002-02
OUT
21-6) and,