r5f21368sdfp Renesas Electronics Corporation., r5f21368sdfp Datasheet - Page 80

• Manufacturer Part Number: r5f21368sdfp
• Description: Renesas Mcu R8c Family / R8c/3xt-a Series
• Manufacturer: Renesas Electronics Corporation.

Under development
R8C/36T-A Group
R01UH0240EJ0001 Rev.0.01
Apr 28, 2011
6.3.2
6.3.2.1
6.3.2.2
The hardware reset is the reset that is caused by the RESET pin. When a low level is applied to the RESET pin
under the condition that the supply voltage meets the recommended operating conditions, the CPU, SFRs, and
I/O ports are initialized. (refer to Table 6.3 Pin States while RESET Pin Level is Low, Figure 6.8 CPU
Register States after Reset, and Tables 3.1 to 3.16 SFR Information).
When the RESET pin is changed from low to high, a program is executed starting at the address indicated by
the reset vector. The low-speed on-chip oscillator clock with no division is automatically selected as the CPU
clock after a reset.
For the states of the SFRs after a reset, refer to 3.2 Special Function Registers (SFRs).
The internal RAM is not initialized. If the RESET pin is set to low while writing to the internal RAM, the RAM
values will be undefined.
Figure 6.3 shows the Hardware Reset Circuit Example and Operation. Figure 6.4 shows the Hardware Reset
Circuit Example (Using External Supply Voltage Detection Circuit) and Operation.
(1) Apply a low level to the RESET pin.
(2) Wait for 10 s.
(3) Apply a high level to the RESET pin.
(1) Apply a low level to the RESET pin.
(2) Let the supply voltage increase until it meets the recommended operating conditions.
(3) Wait for td(P-R) until the internal power supply is stabilized (refer to 28. Electrical Characteristics).
(4) Wait for 10 s.
(5) Apply a high level to the RESET pin.
Hardware Reset
Preliminary document
Specifications in this document are tentative and subject to change.
When Power Supply is Stable
When Power Supply is Turned on
Page 49 of 725
6. Resets