R5F21334CNFP#U0 Renesas Electronics America, R5F21334CNFP#U0 Datasheet - Page 143

• Manufacturer Part Number: R5F21334CNFP#U0
• Description: MCU 1KB FLASH 16K ROM 32-LQFP
• Manufacturer: Renesas Electronics America
• Series: R8C/3x/33Cr

Specifications of R5F21334CNFP#U0

• Core Processor: R8C
• Core Size: 16/32-Bit
• Speed: 20MHz
• Connectivity: I²C, LIN, SIO, SSU, UART/USART
• Peripherals: POR, PWM, Voltage Detect, WDT
• Number Of I /o: 27
• Program Memory Size: 16KB (16K x 8)
• Program Memory Type: FLASH
• Ram Size: 1.5K x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 5.5 V
• Data Converters: A/D 12x10b; D/A 2x8b
• Oscillator Type: Internal
• Operating Temperature: -20°C ~ 85°C
• Package / Case: 32-LQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

R8C/33C Group
REJ09B0570-0100 Rev.1.00 Dec. 14, 2009
Page 113 of 589
9.5
Figure 9.5
The XCIN clock is supplied by the XCIN clock oscillation circuit. This clock is used as the clock source for the
CPU and peripheral function clocks. The XCIN clock oscillation circuit is configured by connecting a resonator
between the XCIN and XCOUT pins. The XCIN clock oscillation circuit includes an on-chip a feedback resistor,
which is disconnected from the oscillation circuit in stop mode in order to reduce the amount of power consumed
by the chip. The XCIN clock oscillation circuit may also be configured by feeding an externally generated clock to
the XCIN pin.
Figure 9.5 shows Examples of XCIN Clock Connection Circuits.
During and after a reset, the XCIN clock stops.
After setting the CM04 bit in the CM0 register to 1 (XCIN-XCOUT pin), the XCIN clock starts oscillating when
the CM03 bit in the CM0 register is set to 0 (XCIN clock oscillates). After the XCIN clock oscillation stabilizes,
the XCIN clock is used as the CPU clock source when the CM07 bit in the CM0 register is set to 1 (XCIN clock).
To input an externally generated clock to the XCIN pin, also set the CM04 bit in the CM0 register to 1 (XCIN-
XCOUT pin). Leave the XCOUT pin open at this time.
This MCU has an on-chip feedback resistor, which can be disabled/enabled by the CM12 bit in the CM1 register.
In stop mode, all clocks including the XCIN clock stop. Refer to 9.7 Power Control for details.
• When CM03 bit in CM0 register is set
XCIN Clock
to 0 (XCIN clock oscillates) and CM04
bit is set to 1 (XCIN-XCOUT pin)
External crystal oscillator circuit
Note:
XCIN
1. Insert a damping resistor and feedback resistor if required. The resistance will vary depending on
(on-chip feedback resistor)
When the oscillation drive capacity is set to low, check that oscillation is stable. If the oscillator
manufacturer's datasheet specifies that a feedback resistor be added to the chip externally,
the oscillator and the oscillation drive capacity setting. Use the value recommended by the oscillator
manufacturer.
insert a feedback resistor between XCIN and XCOUT following the instructions.
Examples of XCIN Clock Connection Circuits
CIN
MCU
Rf
(1)
XCOUT
Rd
COUT
(1)
• When CM03 bit in CM0 register is set
to 1 (XCIN clock stops) and CM04 bit
is set to 1 (XCIN-XCOUT pin)
VSS
VCC
Externally generated clock
XCIN
External clock input circuit
(on-chip feedback resistor)
MCU
9. Clock Generation Circuit
XCOUT
Open