HD6413308 Hitachi Semiconductor, HD6413308 Datasheet - Page 162

• Manufacturer Part Number: HD6413308
• Description: Hitachi Single-Chip MicroComputer
• Manufacturer: Hitachi Semiconductor

6.7 Application Notes
Application programmers should note that the following types of contention can occur in the free-
running timers.
(1) Contention between FRC Write and Clear: If an internal counter clear signal is generated
during the T
takes priority and the write is not performed.
Figure 6-21 shows this type of contention.
(2) Contention between FRC Write and Increment: If an FRC increment pulse is generated
during the T
priority and the FRC is not incremented.
Figure 6-22 shows this type of contention.
3
3
state of a write cycle to the lower byte of the free-running counter, the clear signal
state of a write cycle to the lower byte of the free-running counter, the write takes
Ø
Internal address bus
Internal write signal
FRC clear signal
FRC
Figure 6-21. FRC Write-Clear Contention
Write cycle: CPU write to lower byte of FRC
T
1
147
N
FRC address
T
2
T
3
Figure 6-21
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