SH7046 Datasheet, PDF (358/611 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperH RISC engine Family/SH7046 Series

Section 11 Watchdog Timer
Writing to RSTCSR: RSTCSR must be written by a word access to address H'FFFF8612. It
cannot be written by byte transfer instructions.
Procedures for writing 0 to WOVF (bit 7) and for writing to RSTE (bit 6) and RSTS (bit 5) are
different, as shown in figure 11.7.
To write 0 to 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.
• Writing 0 to the WOVF bit
15
Address: H'FFFF8612
H'A5
87
0
H’00
• Writing to the RSTE and RSTS bits
15
Address: H'FFFF8612
H'5A
87
0
Write data
Figure 11.7 Writing to RSTCSR
Reading from TCNT, TCSR, and RSTCSR: TCNT, TCSR, and RSTCSR are read like other
registers. Use byte transfer instructions. The read addresses are H'FFFF8610 for TCSR,
H'FFFF8611 for TCNT, and H'FFFF8613 for RSTCSR.
Rev. 4.00 Dec 05, 2005 page 314 of 564
REJ09B0270-0400