C541U Datasheet, PDF (14/63 Pages) Siemens Semiconductor Group – 8 BIT CMOS MICROCONTROLLER

C541U
Reset and System Clock
The reset input is an active high input at pin RESET. Since the reset is synchronized internally, the
RESET pin must be held high for at least two machine cycles (12 oscillator periods) while the
oscillator is running. A pulldown resistor is internally connected to V_SS to allow a power-up reset with
an external capacitor only. An automatic reset can be obtained when V_DD is applied by connecting
the RESET pin to V_DD via a capacitor. Figure 6 shows the possible reset circuitries.
V_DD
+
a)
C541U
RESET
b)
C541U
&
RESET
c)
V_DD
V_DD
+
C541U
RESET
Figure 6
Reset Circuitries
Semiconductor Group
12