M16623FG View Datasheet(PDF) -

Reset

Mitsubishi microcomputers

M16C / 62A Group (80-pin)

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 of software resets.) 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.

The RAM is undefined at power on. The initial values must therfore be set. When a reset signal is applied

while the CPU is writing a value to the RAM, the value may be set as unknown due to the termination of the

CPU access.

Figure 1.6.1 shows the example reset circuit. Figure 1.6.2 shows the reset sequence.

RESET

VCC

5V

VCC

0V

5V

RESET

0V

Example when VCC = 5V.

4.0V

0.8V

Figure 1.6.1. Example reset circuit

XIN

Single chip

mode

RESET

BCLK

Address

More than 20 cycles are needed

BCLK 24cycles

FFFFC16

Content of reset vector

FFFFE16

Figure 1.6.2. Reset sequence

14

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