R5F211B1SP#U0 Renesas Electronics America, R5F211B1SP#U0 Datasheet - Page 60

• Manufacturer Part Number: R5F211B1SP#U0
• Description: IC R8C MCU FLASH 4K 20SSOP
• Manufacturer: Renesas Electronics America
• Series: M16C™ M16C/R8C/Tiny/1Br

Specifications of R5F211B1SP#U0

• Core Processor: R8C
• Core Size: 16-Bit
• Speed: 20MHz
• Connectivity: I²C, SIO, SSU, UART/USART
• Peripherals: LED, POR, Voltage Detect, WDT
• Number Of I /o: 13
• Program Memory Size: 4KB (4K x 8)
• Program Memory Type: FLASH
• Ram Size: 384 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 4x10b
• Oscillator Type: Internal
• Operating Temperature: -20°C ~ 85°C
• Package / Case: 20-SSOP
• For Use With: R0K5211B4S001BE - KIT STARTER FOR R8C/18191A1BR0K5211B4S000BE - KIT DEV EVALUATION R8C/1BR0E521174CPE10 - EMULATOR COMPACT R8C/18/19/1
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

R8C/1A Group, R8C/1B Group
Rev.1.30
REJ09B0252-0130
6.2
Figure 6.6
NOTES:
When the RESET pin is connected to the VCC pin via a pull-up resistor of about 5 kΩ, and the VCC pin voltage
level rises, the power-on reset function is enabled and the MCU resets its pins, CPU, and SFR. When a capacitor is
connected to the RESET pin, always keep the voltage to the RESET pin 0.8VCC or more.
When the input voltage to the VCC pin reaches the Vdet1 level or above, the low-speed on-chip oscillator clock
starts counting. When the low-speed on-chip oscillator clock count reaches 32, the internal reset signal is held “H”
and the MCU enters the reset sequence (refer to Figure 6.3). The low-speed on-chip oscillator clock divide by 8 is
automatically selected as the CPU after reset.
Refer to 4. Special Function Registers (SFRs) for the status of the SFR after power-on reset.
The voltage monitor 1 reset is enabled after power-on reset.
Figure 6.6 shows an Example of Power-On Reset Circuit and Operation.
1. The supply voltage must be held within the MCU’s operating voltage range (Vccmin or above) over the sampling time.
2. A sampling clock can be selected. Refer to 7. Voltage Detection Circuit for details.
3. Vdet1 indicates voltage detection level for the voltage detection 1 circuit. Refer to 7. Voltage Detection Circuit for details.
4. Refer to 19. Electrical Characteristics.
Internal reset signal
Power-On Reset Function
Dec 08, 2006
(active “L”)
About
5 kΩ
Example of Power-On Reset Circuit and Operation
V
V
det1
por1
(3)
VCC
RESET
Page 42 of 315
t
w(por1)
t
w(Vpor1–Vdet1)
f
RING-S
1
× 32
Sampling time
RESET
VCC
0 V
0 V
(1, 2)
0.1 V to 2.7 V
t
w(por2)
within td(P-R)
t
w(Vpor2–Vdet1)
V
Vccmin
por2
0.8 VCC or above
f
RING-S
1
× 32
V
det1
6. Resets
(3)