Renesas 7700 FAMILY User Manual page 291

RESET
13.1 Hardware reset
This chapter describes the method to reset the microcomputer. There are two methods to do that: Hardware
reset and Software reset.
13.1 Hardware reset
When the power source voltage satisfies the microcomputer's recommended operating conditions, the
microcomputer is reset by supplying "L" level to the
13.1.1 shows an example of hardware reset timing.
"H"
RESET
"L"
Note: When the clock is stably supplied. (Refer to "13.1.4 Time supplying "L" level to RESET pin.")
Fig. 13.1.1 Example of hardware reset timing
The following explains how the microcomputer operates for terms
After supplying "L" level to the
ns. (Refer to Table 13.1.1.)
______
pin is "L" level and within the term of 4 to 5 cycles of the internal clock φ after the
While the
RESET
______
pin goes from "L" to "H," the microcomputer initializes the central processing unit (CPU) and SFR
RESET
area. At this time, the contents of the internal RAM area become undefined (except when Stop or Wait
mode is terminated). (Refer to Figures 13.1.2 to 13.1.6.)
After , the microcomputer performs "Internal processing sequence after reset." (Refer to Figure 13.1.7.)
The microcomputer executes a program beginning with the address set into the reset vector addresses
which are FFFE
16
13–2
µ
2 s or more
______
pin, the microcomputer initializes pins within a term of several ten
RESET
and FFFF .
16
7751 Group User's Manual
______
pin. This is called a hardware reset. Figure
RESET
φ
4 to 5 cycles of
Internal processing
sequence after a
reset
Program is executed.
to above.