DF2345TE20 Renesas Electronics America, DF2345TE20 Datasheet - Page 430

• Manufacturer Part Number: DF2345TE20
• Description: MCU 5V 128K 100-TQFP
• Manufacturer: Renesas Electronics America
• Series: H8® H8S/2300r

Specifications of DF2345TE20

• Core Processor: H8S/2000
• Core Size: 16-Bit
• Speed: 20MHz
• Connectivity: SCI, SmartCard
• Peripherals: POR, PWM, WDT
• Number Of I /o: 71
• Program Memory Size: 128KB (128K x 8)
• Program Memory Type: FLASH
• Ram Size: 4K x 8
• Voltage - Supply (vcc/vdd): 4.5 V ~ 5.5 V
• Data Converters: A/D 8x10b; D/A 2x8b
• Oscillator Type: Internal
• Operating Temperature: -20°C ~ 75°C
• Package / Case: 100-TQFP, 100-VQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -
• Other names: HD64F2345TE20; HD64F2345TE20

Section 11 Watchdog Timer
11.3
11.3.1
To use the WDT as a watchdog timer, set the WT/IT and TME bits to 1. Software must prevent
TCNT overflows by rewriting the TCNT value (normally be writing H'00) before overflows
occurs. This ensures that TCNT does not overflow while the system is operating normally. If
TCNT overflows without being rewritten because of a system crash or other error, the WDTOVF
signal * is output. This is shown in figure 11.4. This WDTOVF signal * can be used to reset the
system. The WDTOVF signal * is output for 132 states when RSTE = 1, and for 130 states when
RSTE = 0.
If TCNT overflows when 1 is set in the RSTE bit in RSTCSR, a signal that resets the H8S/2345
Group internally is generated at the same time as the WDTOVF signal * . This reset can be selected
as a power-on reset or a manual reset, depending on the setting of the RSTS bit in RSTCSR. The
internal reset signal is output for 518 states.
If a reset caused by a signal input to the RES pin occurs at the same time as a reset caused by a
WDT overflow, the RES pin reset has priority and the WOVF bit in RSTCSR is cleared to 0.
Note: * The WDTOVF pin function is not supported by the F-ZTAT version.
Rev. 4.00 Feb 15, 2006 page 404 of 900
REJ09B0291-0400
Operation
Watchdog Timer Operation