M38B53M4-059FP datasheet(234/355 Pages) MITSUBISHI

Part #	M38B53M4-059FP

Description	8-BIT SINGLE-CHIP MICROCOMPUTER

PDF	355 Pages

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Manufacturer	MITSUBISHI [Mitsubishi Electric Semiconductor]

Direct Link	http://www.mitsubishichips.com

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234 / 355 page

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38B5 Group User’s Manual

APPLICATION

2.8 Watchdog timer

Fig. 2.8.5 Control procedure

2.8.4 Notes on use

q The watchdog timer continues to count even while waiting for stop release. Accordingly, make sure that

watchdog timer does not underflow during this term by writing to the watchdog timer control register

(address 002B16) once before executing the STP instruction, etc.

q Once a “1” is written to the STP instruction disable bit (bit 6) of the watchdog timer control register

(address 002B16), it cannot be programmed to “0” again. This bit becomes “0” after reset.

Figure 2.8.5 shows the control procedure.

Initialization

SEI

CLT

CLD

CPUM (address 003B16)

000XXX002

Main processing

RESET

CPU mode register setting

(single-chip mode, main clock oscillating, high-speed mode)

WDTCON (address 002B16)

00XXXXXX2

Count of watchdog timer start

(STP instruction enabled, WDTH count source)

CLI

qX: This bit is not used here. Set it to “0” or “1” arbitrarily.

M38B53M4-059FP Datasheet(PDF) 234 Page - Mitsubishi Electric Semiconductor