R5F21133DFP RENESAS [Renesas Technology Corp], R5F21133DFP Datasheet - Page 25

• Manufacturer Part Number: R5F21133DFP
• Description: 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY/R8C/Tiny SERIES
• Manufacturer: RENESAS [Renesas Technology Corp]

R8C/13 Group
Rev.1.20
REJ09B0111-0120
Table 5.1 Pin Status When RESET Pin Level is “L”
5. Reset
P1
P3
P0
P4
0
There are three types of resets: a hardware reset, a software reset, and an watchdog timer reset.
There are three kinds of hardware reset: hardware reset 1, hardware reset 2, and power-on reset.
After reset, the low-speed on-chip oscillator clock divided by 8 is automatically selected for the CPU.
5 to
5.1 Hardware Reset
Pin name
to P3
A reset is applied using the RESET pin. When an “L” signal is applied to the RESET pin while the
power supply voltage is within the recommended operating condition, the pins are initialized (see
Table 5.1 “Pin Status When RESET Pin Level is 'L'”). When the input level at the RESET pin is
released from “L” to “H”, the CPU and SFR are initialized, and the program is executed starting
from the address indicated by the reset vector. Figure 5.1 shows the CPU register status after
reset and figure 5.2 shows the reset sequence. The internal RAM is not initialized. If the RESET
pin is pulled “L” while writing to the internal RAM, the internal RAM becomes indeterminate.
Figures 5.3 to 5.4 show the reset circuit example using the hardware reset 1. Refer to Chapter 4,
“Special Function Register (SFR)” for the status of SFR after reset.
Jan 27, 2006
5.1.1 Hardware Reset 1
P4
• When the power supply is stable
(1) Apply an “L” signal to the RESET pin.
(2) Wait for 500 µs (1/f
(3) Apply an “H” signal to the RESET pin.
• Power on
(1) Apply an “L” signal to the RESET pin.
(2) Let the power supply voltage increase until it meets the recommended operating condi-
(3) Wait td(P-R) or more until the internal power supply stabilizes.
(4) Wait for 500 µs (1/f
(5) Apply an “H” signal to the RESET pin.
7
3
, P3
tion.
7
page 14 of 205
Input port
Input port
Input port
Input port
____________
Pin status
RING-S
RING-S
____________
____________
____________
____________
____________
____________
20).
20).
____________
5.1 Hardware Reset
____________
____________