SAF-C164SM Infineon Technologies, SAF-C164SM Datasheet - Page 404

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

If the supply voltage continues to be applied, the realtime clock (RTC) can be kept
running in Power Down mode to maintain a valid system time. This enables a system to
determine the current time and the duration of the period in Power Down mode (by
comparing the current time with a timestamp stored when Power Down mode was
entered). The supply current in this case remains well below 1 mA.
During power down, the voltage at the
and its selected oscillator continue running and the contents of the internal RAM will be
preserved.
With the RTC (and oscillator) disabled, the internal RAM is preserved down to a voltage
of 2.5 V.
Note: When the RTC remains active in Power Down mode, the oscillator which
The total power consumption in Power Down mode depends on the active circuitry
(whether the RTC is on or off) and on the current flowing through the port drivers. To
minimize the consumed current, the RTC and/or all pin drivers can be disabled (pins
switched to tristate) via a central control bitfield in register SYSCON2. If an application
requires one or more port drivers to remain active even in Power Down mode, individual
port drivers can be disabled simply by configuring them for input.
The bus interface pins can be separately disabled by releasing the external bus (disable
all address windows by clearing the BUSACT bits) and switching the ports to input (if
necessary). Of course, the required software in this case must be executed from internal
memory.
User’s Manual
generates the RTC clock signal will continue running.
If the supply voltage is reduced, the specified maximum CPU clock frequency for
this case must be taken into account.
V
DD
21-8
pins can be lowered to 2.7 V while the RTC
Power Management
C164CM/C164SM
Derivatives
V1.0, 2002-02