DF2556FC20DV Renesas Electronics America, DF2556FC20DV Datasheet - Page 438

• Manufacturer Part Number: DF2556FC20DV
• Description: IC H8S/2556 MCU FLASH 144QFP
• Manufacturer: Renesas Electronics America
• Series: H8® H8S/2500r

Specifications of DF2556FC20DV

• Core Processor: H8S/2000
• Core Size: 16-Bit
• Speed: 20MHz
• Connectivity: CAN, I²C, SCI
• Peripherals: POR, PWM, WDT
• Number Of I /o: 104
• Program Memory Size: 512KB (512K x 8)
• Program Memory Type: FLASH
• Ram Size: 32K x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 5.5 V
• Data Converters: A/D 16x10b; D/A 2x8b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 144-QFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

Section 12 Watchdog Timer (WDT)
12.6
12.6.1
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: These registers must be written to by a word transfer instruction.
They cannot be written to by a byte transfer instruction. Refer to figure 12.6.
Both TCNT and TCSR are allocated to the same address when they are written to. When writing
to TCNT, the upper byte must be H'5A and the lower byte must be data to be written to. When
writing to TCSR, the upper byte must be H'A5 and the lower byte must be data to be written to.
Accordingly, the lower byte data is written to TCNT or TCSR.
Rev. 6.00 Sep. 24, 2009 Page 390 of 928
REJ09B0099-0600
Usage Notes
Notes on Register Access
Figure 12.6 Writing to TCNT and TCSR (WDT_0)
Writing to TCNT
Writing to TCSR
Address:
Address:
H'FF74
H'FF74
15
15
H'5A
H'A5
8 7
8 7
Write data
Write data
0
0