r5f71374an80fpv Renesas Electronics Corporation., r5f71374an80fpv Datasheet - Page 555

• Manufacturer Part Number: r5f71374an80fpv
• Description: 32-bit Risc Microcomputer Superh?? Risc Engine Family
• Manufacturer: Renesas Electronics Corporation.

13.3.3
The watchdog timer counter (WTCNT) and watchdog timer control/status register (WTCSR) are
more difficult to write to than other registers. The procedure for writing to these registers is given
below.
Writing to WTCNT and WTCSR: These registers must be written by a word transfer
instruction. They cannot be written by a byte or longword transfer instruction. When writing to
WTCNT, set the upper byte to H'5A and transfer the lower byte as the write data, as shown in
figure 13.2. When writing to WTCSR, set the upper byte to H'A5 and transfer the lower byte as
the write data. This transfer procedure writes the lower byte data to WTCNT or WTCSR.
WTCNT write
WTCSR write
Address: H'FFFFE810
Address: H'FFFFE812
Notes on Register Access
Figure 13.2 Writing to WTCNT and WTCSR
15
15
H'5A
H'A5
8
8
Rev. 1.00 Sep. 21, 2007 Page 529 of 1124
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7
Section 13 Watchdog Timer (WDT)
Write data
Write data
REJ09B0402-0100
0
0