Hitachi H8/3664 Hardware Manual page 247

Contention between Buffer Register Write and Compare Match in Buffer Operation: If a
compare match occurs in the T2 state of a buffer register write cycle, the old data (before being
updated) in the buffer register is transferred to the general data in a buffer operation. Figure 12.36
shows this timing.
φ
Address
Write signal
Compare
match signal
Buffer register
GR
Figure 12.36 Contention between Buffer Register Write and Compare Match
Buffer register
write cycle
T1 T2
Buffer register
address
N M (Buffer register write data)
X
N
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