HD64F3026X25 Renesas Electronics America, HD64F3026X25 Datasheet - Page 386

• Manufacturer Part Number: HD64F3026X25
• Description: MCU 3V 256K 100-TQFP
• Manufacturer: Renesas Electronics America
• Series: H8® H8/300Hr

Specifications of HD64F3026X25

• Core Processor: H8/300H
• Core Size: 16-Bit
• Speed: 25MHz
• Connectivity: SCI, SmartCard
• Peripherals: PWM, WDT
• Number Of I /o: 70
• Program Memory Size: 256KB (256K x 8)
• Program Memory Type: FLASH
• Ram Size: 8K x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 3.6 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: -

Section 11 Watchdog Timer
11.3
Operations when the WDT is used as a watchdog timer and as an interval timer are described
below.
11.3.1
Figure 11.4 illustrates watchdog timer operation. To use the WDT as a watchdog timer, set the
WT/
TCNT value (normally by writing H'00) before overflow occurs. If TCNT fails to be rewritten and
overflows due to a system crash etc., the H8/3024 is internally reset for a duration of 518 states.
The watchdog reset signal can be externally output from the
devices. The reset signal is output externally for 132 states. External output can be enabled or
disabled by the RSTOE bit in RSTCSR. Note that there is no
chip flash memory.
A watchdog reset has the same vector as a reset generated by input at the
distinguish a
If a
Rev. 2.00 Sep 20, 2005 page 346 of 800
REJ09B0260-0200
R E S
I T
and TME bits to 1 in TCSR. Software must prevent TCNT overflow by rewriting the
H'FF
TCNT count
value
H'00
Internal
reset signal
RESO
reset and a watchdog reset occur simultaneously, the
Operation
Watchdog Timer Operation
R E S
reset from a watchdog reset by checking the WRST bit in RSTCSR.
Figure 11.4 Operation in Watchdog Timer Mode
Start
H'00 written
in TCNT
OVF = 1
WDT overflow
132 states
Reset
518 states
R E S O
R E S O
R E S
TME set to 1
reset takes priority.
pin to reset external system
pin in the versions with on-
R E S
H'00 written
in TCNT
pin. Software can