Hitachi SH7095 Hardware User Manual page 326

Writing to the WTCNT and WTCSR: These registers must be written by a word transfer
instruction. They cannot be written by byte or longword transfer instructions. The WTCNT and
WTCSR both have the same write address. The write data must be contained in the lower byte of
the written word. The upper byte must be H'5A (for the WTCNT) or H'A5 (for the WTCSR)
(figure 12.2). This transfers the write data from the lower byte to the WTCNT or WTCSR.
Writing to the
WTCNT
Address:
Writing to the
WTCSR
Address:
Writing to the RSTCSR: The RSTCSR must be written by a word access to address
H'FFFFFE82. It cannot be written by byte or longword 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.
Writing 0 to the WOVF bit
Address:
Writing to the RSTE and RSTS bits
Address:
H'FFFFFE80
H'FFFFFE80
Figure 12.2 Writing to the WTCNT and WTCSR
H'FFFFFE82
H'FFFFFE82
Figure 12.3 Writing to the RSTCSR
15
H'5A
15
H'A5
15
H'A5
15
H'5A
8 7
Write data
8 7
Write data
8 7
H'00
8 7
Write data
Hitachi 315
0
0
0
0