HD64F36077GHV Renesas Electronics America, HD64F36077GHV Datasheet - Page 297

• Manufacturer Part Number: HD64F36077GHV
• Description: 16BIT MCU FLASH 56K, SMD, LQFP64
• Manufacturer: Renesas Electronics America

Specifications of HD64F36077GHV

• No. Of I/o's: 47
• Ram Memory Size: 4KB
• Cpu Speed: 20MHz
• No. Of Timers: 4
• Digital Ic Case Style: LQFP
• Supply Voltage Range: 4.5V
• Core Size: 16bit
• Program Memory Size: 56KB
• Oscillator Type: External Only
• Controller Family/series: H8/300H
• Peripherals: ADC
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

The watchdog timer is an 8-bit timer that can generate an internal reset signal for this LSI if a
system crash prevents the CPU from writing to the timer counter, thus allowing it to overflow.
The block diagram of the watchdog timer is shown in figure 14.1.
14.1
• Selectable from nine counter input clocks.
• Reset signal generated on counter overflow
• The watchdog timer is enabled in the initial state.
WDT0110A_000020030700
Eight clock sources (φ/64, φ/128, φ/256, φ/512, φ/1024, φ/2048, φ/4096, and φ/8192) or the
WDT dedicated internal oscillator can be selected as the timer-counter clock. When the WDT
dedicated internal oscillator is selected, it can operate as the watchdog timer in any operating
mode.
An overflow period of 1 to 256 times the selected clock can be set.
It starts operating after the reset state is canceled.
Features
internal oscillator
WDT dedicated
[Legend]
TCSRWD: Timer control/status register WD
TCWD:
PSS:
TMWD:
φ
Figure 14.1 Block Diagram of Watchdog Timer
Section 14 Watchdog Timer
Timer counter WD
Prescaler S
Timer mode register WD
CLK
PSS
TCSRWD
TMWD
TCWD
Rev. 1.00 Sep. 16, 2005 Page 267 of 490
Section 14 Watchdog Timer
Internal reset
signal
REJ09B0216-0100