M16C80 Datasheet, PDF (29/358 Pages) Renesas Technology Corp – RENESAS 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/80 SERIES

M16C/80 Group
4. Reset
4. 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.
Figure 4.1 shows the example reset circuit. Figure 4.2 shows the reset sequence.
RESET
VCC
Recommended
operating
voltage
VCC
0V
RESET
0V
Equal to or less
than 0.2VCC
Equal to or less
than 0.2VCC
More than 20 cycles of XIN
are needed.
Figure 4.1 Example reset circuit
XIN
Microprocessor
mode BYTE = “H”
More than 20 cycles are needed
RESET
40 to 45 BCLK cycles
BCLK
Address
FFFFFC16
FFFFFD16
FFFFFE16
Content of reset vector
FFFFFF16
RD
WR
CS0
Microprocessor
mode BYTE = “L”
Address
FFFFFC16
FFFFFE16
Content of reset vector
RD
WR
CS0
Single chip
mode
Address
Figure 4.2 Reset sequence
FFFFFC16 Content of reset vector
FFFFFE16
Rev.1.00 Aug. 02, 2005 ^{Page 18} of 329
REJ09B0187-0100