M30222 Datasheet, PDF (13/237 Pages) Mitsubishi Electric Semiconductor – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER

dUevnedloerpment
Specifications in this manual are tentative and subject to change
MITSUBISHI MICROCOMPUTERS
M30222 Group
Rev. G
Reset
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
Reset
There are two kinds of resets; hardware and software. In both cases, operation is the same after the
reset. (See “Software Reset” for details.) This section explains on hardware resets.
When the supply voltage is in the range where operation is guaranteed, a reset is effected by holding the
reset pin level “L” (0.2VCC max.) for at least 20 cycles. When the reset pin level is then returned to the
“H” level while main clock is stable, the reset status is cancelled and program execution resumes from
the address in the reset vector table.
Figure 1.8 shows an example reset circuit. Figure 1.9 shows a reset sequence. Table 1.4 shows the pin
status when reset pin level is "L".
5V
VCC
4.0V
0V
RESET
VCC
5V
Example when Vcc = 5V
RESET
0V
0.8V
Fig. 1.8. Example of Reset Circuit
Xin
More than 20 cycles are needed
RESET
BCLK
BCLK
24cycles
Fig. 1.9. Reset sequence
Address
FFFFC16
Content of reset
vector
FFFFE16
Table 1.4. Pin status when Reset pin level is "L"
Pin name
Status
P3, P4
Input port (with a pull-up resistor)
P6 to P10
Input port (floating)
SEG0 to SEG23
COM0 to COM3
"H" level is output
"H" level is output
1-14