UPD78F1146AGB-GAH-AX Renesas Electronics America, UPD78F1146AGB-GAH-AX Datasheet - Page 297

• Manufacturer Part Number: UPD78F1146AGB-GAH-AX
• Description: MCU 16BIT 78K0R/KX3 64-LQFP
• Manufacturer: Renesas Electronics America
• Series: 78K0R/Kx3r

Specifications of UPD78F1146AGB-GAH-AX

• Core Processor: 78K/0R
• Core Size: 16-Bit
• Speed: 20MHz
• Connectivity: 3-Wire SIO, I²C, LIN, UART/USART
• Peripherals: DMA, LVD, POR, PWM, WDT
• Number Of I /o: 50
• Program Memory Size: 256KB (256K x 8)
• Program Memory Type: FLASH
• Ram Size: 12K x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: *
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

8.4.4 Setting watchdog timer interval interrupt
generated when 75% of the overflow time is reached.
Depending on the setting of bit 7 (WDTINT) of an option byte (000C0H), an interval interrupt (INTWDTI) can be
Caution When operating with the X1 oscillation clock after releasing the STOP mode, the CPU starts
Remark The watchdog timer continues counting even after INTWDTI is generated (until ACH is written to the
Remarks 1. If the overflow time is set to 2
WDTINT
0
1
operating after the oscillation stabilization time has elapsed.
Therefore, if the period between the STOP mode release and the watchdog timer overflow is
short, an overflow occurs during the oscillation stabilization time, causing a reset.
Consequently, set the overflow time in consideration of the oscillation stabilization time when
operating with the X1 oscillation clock and when the watchdog timer is to be cleared after the
STOP mode release by an interval interrupt.
WDTE register). If ACH is not written to the WDTE register before the overflow time, an internal reset
signal is generated.
2. f
Interval interrupt is used.
Interval interrupt is generated when 75% of overflow time is reached.
<When window open period is 25%>
• Overflow time:
• Window close time:
• Window open time:
IL
Window close time
Window open time
: Internal low-speed oscillation clock frequency
= 3.56 to 3.88 ms
2
0 to 2
2
10
10
/f
/f
IL
IL
Table 8-5. Setting of Watchdog Timer Interval Interrupt
10
(MAX.) = 2
(MIN.) × (1 − 0.25) to 2
/f
IL
(MIN.) × (1 − 0.25) = 0 to 2
10
CHAPTER 8 WATCHDOG TIMER
/264 kHz (MAX.) = 3.88 ms
0 to 3.56 ms
3.56 to 3.88 ms
User’s Manual U17854EJ9V0UD
Use of Watchdog Timer Interval Interrupt
25%
10
/f
IL
10
, the window close time and open time are as follows.
/f
IL
(MAX.) = 2
10
0 to 2.37 ms
2.37 to 3.88 ms
/216 kHz (MIN.) × 0.75 = 0 to 3.56 ms
Setting of Window Open Period
50%
10
/216 kHz (MIN.) × 0.75 to 2
0 to 0.119 ms
0.119 to 3.88 ms
75%
None
0 to 3.88 ms
10
/264 kHz (MAX.)
100%
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