DF2437FV Renesas Electronics America, DF2437FV Datasheet - Page 477

• Manufacturer Part Number: DF2437FV
• Description: IC H8S/2437 MCU FLASH 128QFP
• Manufacturer: Renesas Electronics America
• Series: H8® H8S/2400r

Specifications of DF2437FV

• Core Processor: H8S/2600
• Core Size: 16-Bit
• Speed: 20MHz
• Connectivity: I²C, SCI
• Peripherals: POR, PWM, WDT
• Number Of I /o: 85
• Program Memory Size: 256KB (256K x 8)
• Program Memory Type: FLASH
• Ram Size: 16K x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 3.6 V
• Data Converters: A/D 16x10b
• Oscillator Type: Internal
• Operating Temperature: -20°C ~ 75°C
• Package / Case: 128-QFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

15.2
The WDT has the following registers. To prevent accidental overwriting, TCNT and TCSR have
to be written to in a method different from normal registers. For details, see section 15.5.1, Notes
on Register Access. For details on the system control register, see section 3.2.2, System Control
Register (SYSCR).
• Timer counter (TCNT)
• Timer control/status register (TCSR)
15.2.1
TCNT is an 8-bit readable/writable up-counter.
TCNT is initialized to H'00 when the TME bit in the timer control/status register (TCSR) is
cleared to 0.
15.2.2
TCSR selects the clock source to be input to TCNT, and the timer mode.
Bit
7
6
Bit Name Initial Value R/W
OVF
WT/IT
Register Descriptions
Timer Counter (TCNT)
Timer Control/Status Register (TCSR)
0
0
R/(W)* Overflow Flag
R/W
Description
Indicates that TCNT has overflowed (changes from H'FF
to H'00).
[Setting condition]
When TCNT overflows (changes from H'FF to H'00)
When internal reset request generation is selected in
watchdog timer mode, this bit is cleared automatically by
the internal reset.
[Clearing conditions]
•
•
Timer Mode Select
Selects whether the WDT is used as a watchdog timer or
interval timer.
0: Interval timer mode
1: Watchdog timer mode
When TCSR is read when OVF = 1, then 0 is written
to OVF
When 0 is written to TME
Rev.2.00 May. 28, 2009 Page 437 of 732
REJ09B0059-0200