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RESET

7733 Group User’s Manual

13–2

RESET

“H”

“L”

4 to 5 cycles of

internal clock

2 s or more

Internal processing

sequence after reset

Program executed

13.1 Hardware reset

How to reset the microcomputer is described below. There are two methods to reset the microcomputer:

hardware reset and software reset.

13.1 Hardware reset

When the power source voltage satisfies the recommended operating conditions, the microcomputer is reset

______

by applying “L” level to pin RESET. (This is called “Hardware reset.”) Figure 13.1.1 shows an example of

hardware reset timing.

The microcomputer’s operation during periods to is described below.

______

After “L” level is applied to pin RESET, pins are initialized within a period of several ten ns. (Refer to

Table 13.1.1.)

______

While pin RESET is at “L” level or within a period of 4 to 5 cycles of internal clock

φ after pin RESET’s

level changes from “L” to “H,” the central processing unit (CPU) and SFR area are initialized. At this time,

the contents of the internal RAM area is undefined (except the cases where the stop or wait mode is

terminated.). Refer to Figures 13.1.2 to 13.1.6.

After , “Internal processing sequence after reset” is performed. Refer to Figure 13.1.7.

A program is executed beginning with the address set in the reset vector addresses (addresses FFFE16

and FFFF16).

Fig. 13.1.1 Example of hardware reset timing (when main clock is stably supplied.)

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