HD6477021X20V Renesas Electronics America, HD6477021X20V Datasheet - Page 109

• Manufacturer Part Number: HD6477021X20V
• Description: MCU 5V 32K PB-FREE 100-TQFP
• Manufacturer: Renesas Electronics America
• Series: SuperH® SH7020r

Specifications of HD6477021X20V

• Core Processor: SH-1
• Core Size: 32-Bit
• Speed: 20MHz
• Connectivity: EBI/EMI, SCI
• Peripherals: DMA, POR, PWM, WDT
• Number Of I /o: 32
• Program Memory Size: 32KB (32K x 8)
• Program Memory Type: OTP
• Ram Size: 1K x 8
• Voltage - Supply (vcc/vdd): 4.5 V ~ 5.5 V
• Oscillator Type: Internal
• Operating Temperature: -20°C ~ 75°C
• Package / Case: 100-TQFP, 100-VQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Data Converters: -

7.1
The SuperH microcomputer has a built-in clock pulse generator (CPG) that supplies the LSI and
external devices with a clock pulse. The CPG makes the LSI run at the oscillation frequency of the
crystal resonator. The CPG consists of an oscillator and a duty cycle correcting circuit (figure 7.1).
The CPG can be made to generate a clock signal by connecting it to a crystal resonator or by
inputting an external clock. (The CPG is halted in standby mode.)
7.2
Clock pulses can be supplied from a connected crystal resonator or an external clock.
7.2.1
Circuit Configuration: A crystal resonator can be connected as shown in figure 7.2. Use the
damping resistance Rd shown in table 7.1. Use an AT-cut parallel resonating crystal with a
frequency equal to the system clock (CK) frequency. Connect load capacitors (C
shown in the figure. The clock pulse produced by the crystal resonator and internal pulse generator
is sent to the duty cycle correction circuit where its duty cycle is corrected. It is then supplied to
the LSI and to external devices.
System clock
Overview
Clock Source
Connecting a Crystal Resonator
EXTAL
XTAL
Section 7 Clock Pulse Generator (CPG)
CK
Figure 7.1 Block Diagram of the Clock Pulse Generator
Oscillator
Duty correcting
circuit
CPG
L1
Internal
clock ( )
and C
RENESAS 89
L2
) as