m30262f8gp Renesas Electronics Corporation., m30262f8gp Datasheet - Page 18

• Manufacturer Part Number: m30262f8gp
• Description: Renesas 16-bit Cmos Single-chip Microcomputer M16c Family / M16c/20 Series
• Manufacturer: Renesas Electronics Corporation.

Reset
12
Reset
There are two types of reset: a hardware reset and a software reset (See “Software Reset” for details on
software resets.)
Hardware reset
There are two kinds of hardware reset: hardware reset 1 and hardware reset 2.
Hardware reset 1
Hardware reset 2
A reset is applied using the RESET pin. When a low-level signal (“L”) is applied to the RESET pin,
while the power supply voltage is within the recommended operating voltage, the pins are initialized
(see Table 1.5.1). When the input level of the RESET pin is released from low to high, the CPU and
SFR are initialized. The program is executed starting from the address indicated by the reset vector.
The internal RAM is not initialized. If the RESET pin is pulled low while writing to the internal RAM, the
internal RAM becomes indeterminate.
Figure 1.5.1 shows an example of the reset circuit. Table 1.5.1 shows the status of the other pins while
the RESET pin is “L”. Figure 1.5.2 shows the reset sequence. Figure 1.5.3 shows the status of the
CPU registers. Refer to the SFR section on the status of SFR registers after reset.
1. When the power supply is stable (warm start)
2. Power on (cold start)
This reset is generated by the microcomputer's internal voltage detection circuit. The voltage detec-
tion circuit monitors the voltage supplied to the V
voltage drops to V
enabled). When the input voltage increases so it is greater than V
initialized, and the program is executed starting from the address indicated by the reset vector. After
V
registers after the reset is similar to that of hardware reset 1.
Take note, however, that the value of VC26 has no effect in stop mode. Therefore, a reset is not
applied even if the V
DET3
Preliminary Specifications Rev. 0.9
is detected, it takes about 2ms before the program is executed. The status of the pins and
Specifications in this manual are tentative and subject to change.
(1) Apply a low-level signal to the RESET pin
(2) Supply at least 20 clock cycles to the XIN pin
(3) Apply a high-level signal to the RESET pin
(1) Apply a low-level signal to the RESET pin
(2) Turn on or increase the power supply voltage until it meets the recommended operation
voltage.
(3) Wait at least 2ms for the power supply to stabilize
(4) Supply at least 20 clock cycles to the XIN pin
(5) Apply a high-level signal to the RESET pin
DET3
CC
or less while VCR2 register's VC26 bit is equal to “1” (V
input voltage drops to V
Renesas Technology Corp.
DET3
CC
or lower.
pin. A reset is generated when the V
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
DET3
, the CPU, SFR, and pins are
DET3
M16C/26 Group
detection circuit
CC
input