3069RF-ZTAT Datasheet, PDF (387/1003 Pages) Renesas Technology Corp – RENESAS 16-BIT SINGLE-CHIP MICROCOMPUTER

Contention between 16TCNT Byte Write and Increment: If an increment pulse occurs in the T₂
or T₃ state of a 16TCNT byte write cycle, writing takes priority and 16TCNT is not incremented.
The byte data for which a write was not performed is not incremented, and retains its pre-write
value. See figure 9.39, which shows an increment pulse occurring in the T₂ state of a byte write to
16TCNTH.
16TCNTH byte write cycle
T₁
T₂
T₃
φ
Address bus
16TCNTH address
Internal write signal
16TCNT input clock
16TCNTH
16TCNTL
N
M
16TCNT write data
X
X+1
X
Figure 9.39 Contention between 16TCNT Byte Write and Increment
Rev. 5.0, 09/04, page 365 of 978