DF2134AFA20V Renesas Electronics America, DF2134AFA20V Datasheet - Page 436

• Manufacturer Part Number: DF2134AFA20V
• Description: IC H8S/2100 MCU FLASH 80QFP
• Manufacturer: Renesas Electronics America
• Series: H8® H8S/2100r

Specifications of DF2134AFA20V

• Core Processor: H8S/2000
• Core Size: 16-Bit
• Speed: 20MHz
• Connectivity: IrDA, SCI
• Peripherals: POR, PWM, WDT
• Number Of I /o: 58
• Program Memory Size: 128KB (128K x 8)
• Program Memory Type: FLASH
• Ram Size: 4K x 8
• Voltage - Supply (vcc/vdd): 4 V ~ 5.5 V
• Data Converters: A/D 8x10b; D/A 2x8b
• Oscillator Type: Internal
• Operating Temperature: -20°C ~ 75°C
• Package / Case: 80-QFP
• For Use With: 3DK2166 - DEV EVAL KIT H8S/2166
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

Section 14 Watchdog Timer (WDT)
Bit 3—External Reset (XRST): Indicates the reset source. When the watchdog timer is used, a
reset can be generated by watchdog timer overflow in addition to external reset input. XRST is a
read-only bit. It is set to 1 by an external reset, and when the RST/NMI bit is 1, is cleared to 0 by
an internal reset due to watchdog timer overflow.
Bit 3
XRST
0
1
14.2.4
The watchdog timer’s TCNT and TCSR registers differ from other registers in being more difficult
to write to. The procedures for writing to and reading these registers are given below.
Writing to TCNT and TCSR (Example of WDT0): These registers must be written to by a word
transfer instruction. They cannot be written to with byte transfer instructions.
Figure 14.2 shows the format of data written to TCNT and TCSR. TCNT and TCSR both have the
same write address. For a write to TCNT, the upper byte of the written word must contain H'5A
and the lower byte must contain the write data. For a write to TCSR, the upper byte of the written
word must contain H'A5 and the lower byte must contain the write data. This transfers the write
data from the lower byte to TCNT or TCSR.
Reading TCNT and TCSR (Example of WDT0): These registers are read in the same way as
other registers. The read addresses are H'FFA8 for TCSR, and H'FFA9 for TCNT.
Rev. 4.00 Jun 06, 2006 page 380 of 1004
REJ09B0301-0400
TCNT write
TCSR write
Figure 14.2 Format of Data Written to TCNT and TCSR (Example of WDT0)
Notes on Register Access
Address: H'FFA8
Address: H'FFA8
Description
Reset is generated by watchdog timer overflow
Reset is generated by external reset input
15
15
H'5A
H'A5
8 7
8 7
Write data
Write data
(Initial value)
0
0