HD6477021X20V Renesas Electronics America, HD6477021X20V Datasheet - Page 356

• 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: -

12.4
12.4.1
If a timer counter clock pulse is generated during the T3 state of a write cycle to the TCNT, the
write takes priority and the timer counter is not incremented (figure 12.8).
12.4.2
If the values of bits CKS2–CKS0 are altered while the WDT is running, the count may increment
incorrectly. Always stop the watchdog timer (by clearing the TME bit to 0) before changing the
values of bits CKS2–CKS0.
12.4.3
To prevent incorrect operation, always stop the watchdog timer (by clearing the TME bit to 0)
before switching between interval timer mode and watchdog timer mode.
RENESAS 338
Usage Notes
TCNT Write and Count Up Contention
Changing CKS2-CKS0 Bit Values
Changing Watchdog Timer/Interval Timer Modes
write signal
input clock
Address
Internal
Figure 12.8 Contention between TCNT Write and Increment
TCNT
TCNT
CK
T1
TCNT write cycle
TCNT address
N
T2
Counter write data
T3
M