DS72030W200FPV Renesas Electronics America, DS72030W200FPV Datasheet - Page 720

• Manufacturer Part Number: DS72030W200FPV
• Description: MPU, 32BIT, SH7203, ROMLESS, 240QFP
• Manufacturer: Renesas Electronics America
• Series: SH7200r

Specifications of DS72030W200FPV

• Core Size: 32bit
• Program Memory Size: 32KB
• Cpu Speed: 200MHz
• Digital Ic Case Style: QFP
• No. Of Pins: 240
• Supply Voltage Range: 1.1V To 1.3V
• Operating Temperature Range: -20°C To +85°C
• Svhc: No SVHC
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Section 13 Watchdog Timer (WDT)
13.5
Pay attention to the following points when using the WDT in either the interval timer or watchdog
timer mode.
13.5.1
After timer operation has started, the period from the power-on reset point to the first count up
timing of WTCNT varies depending on the time period that is set by the TME bit of WTCSR. The
shortest such time period is thus one cycle of the peripheral clock, Pφ, while the longest is the
result of frequency division according to the value in the CKS[2:0] bits. The timing of subsequent
incrementation is in accord with the selected frequency division ratio. Accordingly, this time
difference is referred to as timer variation.
This also applies to the timing of the first incrementation after WTCNT has been written to during
timer operation.
13.5.2
When the value in WTCNT reaches H'FF, the WDT assumes that an overflow has occurred.
Accordingly, when H'FF is set in WTCNT, an interval timer interrupt or WDT reset will occur
immediately, regardless of the current clock selection by the CKS[2:0] bits.
13.5.3
When the value in WTCNT is H'FF, the IOVF flag in WTCSR cannot be cleared.
Only clear the IOVF flag when the value in WTCNT has either become H'00 or been changed to a
value other than H'FF.
Rev. 3.00 Sep. 28, 2009 Page 688 of 1650
REJ09B0313-0300
Usage Notes
Timer Variation
Prohibition against Setting H'FF to WTCNT
Interval Timer Overflow Flag