m37905 Renesas Electronics Corporation., m37905 Datasheet - Page 49

• Manufacturer Part Number: m37905
• Description: Mitsubishi 16-bit Single-chip Microcomputer 7700 Family / 7900 Series
• Manufacturer: Renesas Electronics Corporation.

RESET
3.1 Reset operation
Fig. 3.1.4 Example of power-on reset circuit
3-4
3.1.3 Power-on reset
The following describes the operation of the microcomputer at power-on reset.
Figure 3.1.3 shows the power-on reset conditions.
Figure 3.1.4 shows an example of a power-on reset
circuit.
After the voltage level at pin Vcc meets the
recommended operating conditions and the oscillator’s
operation is stabilized (See Figure 3.1.3.), apply “L”
level of voltage to pin RESET for 10
When an oscillator is used, the time required for
stabilizing oscillation depends on the oscillator. For
details, contact the oscillator manufacturer.
After powered on, within the several ten cycles of f
operating conditions with the voltage level at pin RESET = “L,” the microcomputer initializes pins; refer to
section “3.2 Pin state.”
SFR area within a period of 8 to 9 cycles of f
refer to section “3.3 State of internal area.”)
Internal processing sequence after reset.”
vector addresses (addresses FFFE
After the voltage level at pin RESET goes from “L” to “H,” the microcomputer initializes the CPU and
After
The microcomputer executes a program beginning with the address which has been set into the reset
, the microcomputer performs “Internal processing sequence after reset.”; refer to section “3.4
27 k
10 k
The delay time is about 11 ms when C
t
d
2
0.34
IN
16
7905 Group User’s Manual Rev.1.0
GND
Delay
capacity
1
3
s or more.
C
V
and FFFF
CC
d
M51957AL
[ s], C
OUT
5
4
d
sys
: [pF]
sys
. (Contents of the internal RAM area become undefined;
16
C
).
after the voltage level at pin Vcc meets the recommended
d
Fig. 3.1.3 Power-on reset conditions
47
RESET
V
X
CC
IN
d
0 V
0 V
0 V
= 0.033 F.
Powered on there
SW
RESET
GND
V
V
CC
SS
M37905
Oscillation stabilized
V
5 V
CC
level
10 s
0.2 V
CC
level