HD6417034B RENESAS [Renesas Technology Corp], HD6417034B Datasheet - Page 371

• Manufacturer Part Number: HD6417034B
• Description: 32-Bit RISC Microcomputer
• Manufacturer: RENESAS [Renesas Technology Corp]

address. The write data must be contained in the lower byte of the written word. The upper byte
must be H'5A (for TCNT) or H'A5 (for TCSR) (figure 12.2). This transfers the write data from the
lower byte to TCNT or TCSR.
Writing to RSTCSR: RSTCSR must be written by a word access to address H'5FFFFFBA. It
cannot be written by byte transfer instructions. Procedures for writing 0 in WOVF (bit 7) and for
writing to RSTE (bit 6) and RSTS (bit 5) are different, as shown in figure 12.3. To write 0 in the
WOVF bit, the write data must be H'A5 in the upper byte and H'00 in the lower byte. This clears
the WOVF bit to 0. The RSTE and RSTS bits are not affected. To write to the RSTE and RSTS
bits, the upper byte must be H'5A and the lower byte must be the write data. The values of bits 6
and 5 of the lower byte are transferred to the RSTE and RSTS bits, respectively. The WOVF bit is
not affected.
Reading from TCNT, TCSR, and RSTCSR: TCNT, TCSR, and RSTCSR are read like other
registers. Use byte transfer instructions. The read addresses are H'5FFFFB8 for TCSR,
H'5FFFFB9 for TCNT, and H'5FFFFBB for RSTCSR.
Writing 0 to the WOVF bit
Address:
Writing to the RSTE and RSTS bits
Address:
Writing to TCNT
Address:
Writing to TCSR
Address:
H'5FFFFBA
H'5FFFFBA
H'5FFFFB8
H'5FFFFB8
Figure 12.2 Writing to TCNT and TCSR
Figure 12.3 Writing to RSTCSR
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H'5A
H'A5
H'A5
H'5A
8
8
8
8
Section 12 Watchdog Timer (WDT)
7
7
7
7
Write data
Write data
Write data
REJ09B0272-0700
H'00
0
0
0
0