HD64F2638F20J Renesas Electronics America, HD64F2638F20J Datasheet - Page 489

• Manufacturer Part Number: HD64F2638F20J
• Description: IC H8S MCU FLASH 256K 128-QFP
• Manufacturer: Renesas Electronics America
• Series: H8® H8S/2600r

Specifications of HD64F2638F20J

• Core Processor: H8S/2600
• Core Size: 16-Bit
• Speed: 20MHz
• Connectivity: CAN, SCI, SmartCard
• Peripherals: Motor Control PWM, POR, PWM, WDT
• Number Of I /o: 72
• Program Memory Size: 256KB (256K x 8)
• Program Memory Type: FLASH
• Ram Size: 16K x 8
• Voltage - Supply (vcc/vdd): 4.5 V ~ 5.5 V
• Data Converters: A/D 12x10b; D/A 2x8b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 128-QFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -

H8S/2639, H8S/2638, H8S/2636,
H8S/2630, H8S/2635 Group
12.3
12.3.1
To use the WDT as a watchdog timer, set the WT/IT bit in TCSR and the TME bit to 1. Software
must prevent TCNT overflows by rewriting the TCNT value (normally by writing H'00) before
overflow occurs. This ensures that TCNT does not overflow while the system is operating
normally. If TCNT overflows without being rewritten because of a system malfunction or other
error, an internal reset is issued, in the case of WDT0, if the RSTE bit in RSTCSR is set to 1.
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.
In the case of WDT1, the chip is reset, or an NMI interrupt request is generated, for 516 system
clock periods (516φ) (515 or 516 clock periods when the clock source is φ/SUB * (PSS = 1)). This
is illustrated in figure 12-4 (b).
An NMI request from the watchdog timer and an interrupt request from the NMI pin are both
treated as having the same vector. So, avoid handling an NMI request from the watchdog timer
and an interrupt request from the NMI pin at the same time.
Note: * Subclock functions (subactive mode, subsleep mode, and watch mode) are available in the
REJ09B0103-0800 Rev. 8.00
May 28, 2010
U-mask and W-mask versions, and H8S/2635 Group only. These functions cannot be used
with the other versions.
Operation
Watchdog Timer Operation
Section 12 Watchdog Timer
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