HD6475348R Datasheet, PDF (262/487 Pages) Hitachi Semiconductor – Single-Chip Microcomputer

Write to TCNT
Address
15
H'FFEC
H'5A
87
0
Write data
Write to TCSR
Address
15
H'FFEC
H'A5
87
0
Write data
Figure 13-2 Writing to TCNT and TCSR
Writing to RSTCSR: The RSTCSR must be written by moving word data to address H'FF14. It
cannot be written by byte access.
The upper byte of the word must contain a password. Separate passwords are used for clearing the
WRST bit and for writing a 1 or 0 to the RSTOE bit.
To clear the WRST bit, the word written at address H'FF14 must contain the password H'A5 in the
upper byte and the data H'00 in the lower byte. This clears the WRST bit to 0.
To set or clear the RSTOE bit, the word written at address H'FF14 must contain the password
H'5A in the upper byte and the write data in the lower byte. The value of bit 6 in the lower byte is
written in the RSTOE bit.
These write operations are illustrated in figure 13-3.
To write 0 to the WRST bit
15
87
0
Address
H'FF14
H'A5
H'00
To write to the RSTOE bit
15
Address
H'FF14
H'5A
87
0
Write data
Figure 13-3 Writing to RSTCSR
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