DF2117VT20V Renesas Electronics America, DF2117VT20V Datasheet - Page 440

• Manufacturer Part Number: DF2117VT20V
• Description: MCU 16BIT FLASH 3V 160K 144-TQFP
• Manufacturer: Renesas Electronics America
• Series: H8® H8S/2100r

Specifications of DF2117VT20V

• Core Processor: H8S/2600
• Core Size: 16-Bit
• Speed: 20MHz
• Connectivity: FIFO, I²C, LPC, SCI, SmartCard
• Peripherals: POR, PWM, WDT
• Number Of I /o: 112
• Program Memory Size: 160KB (160K x 8)
• Program Memory Type: FLASH
• Ram Size: 8K x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 3.6 V
• Data Converters: A/D 16x10b
• Oscillator Type: External
• Operating Temperature: -20°C ~ 75°C
• Package / Case: 144-TQFP, 144-VQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

14.4
14.4.1
To use the WDT as a watchdog timer, set the WT/IT bit and the TME bit in TCSR to 1. While the
WDT is used as a watchdog timer, if TCNT overflows without being rewritten because of a
system malfunction or another error, an internal reset or NMI interrupt request is generated. TCNT
does not overflow while the system is operating normally. Software must prevent TCNT
overflows by rewriting the TCNT value (normally be writing H'00) before overflows occurs.
If the RST/NMI bit of TCSR is set to 1, when the TCNT overflows, an internal reset signal for this
LSI is issued for 518 system clocks as shown in figure 14.2. If the RST/NMI bit is cleared to 0,
when the TCNT overflows, an NMI interrupt request is generated.
An internal reset request from the watchdog timer and a reset input from the RES pin are
processed in the same vector. Reset source can be identified by the XRST bit status in SYSCR.
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 XRST bit in SYSCR is set to 1.
An NMI interrupt request from the watchdog timer and an interrupt request from the NMI pin are
processed in the same vector. Do not handle an NMI interrupt request from the watchdog timer
and an interrupt request from the NMI pin at the same time.
Rev. 2.00 Sep. 28, 2009 Page 398 of 994
REJ09B0452-0200
Operation
Watchdog Timer Mode
Internal reset
signal
[Legned]
WT/IT:
TME:
OVF:
Note * After the OVF bit becomes 1, it is cleared to 0 by an internal reset.
Figure 14.2 Watchdog Timer Mode (RST/NMI = 1) Operation
The XRST bit is also cleared to 0.
Timer mode select bit
Timer enable bit
Overflow flag
H'FF
H'00
TCNT value
WT/IT = 1
TME = 1
Write H'00 to
TCNT
518 System clocks
Overflow
OVF = 1*
WT/IT = 1
TME = 1
Write H'00 to
TCNT
Time