SH7058 Datasheet, PDF (454/1130 Pages) Renesas Technology Corp – Renesas SuperHTM RISC engine

Contention between TCNT Write and Increment: If a write to a channel 0 to 11 free-running
counter (TCNT0, TCNT1A, TCNT1B, TCNT2A, TCNT2B, TCNT3 to TCNT5, TCNT6A to
TCNT6D, TCNT7A to TCNT7D, TCNT10A to TCNT10H, TCNT11), down-counter (DCNT8A
to DCNT8P), or event counter 9 (ECNT9A to ECNT9F) is performed while that counter is
counting up or down, the write to the counter has priority and the counter is not incremented or
decremented.
The timing in this case is shown in figure 11.65. In this example, the CPU writes H'5555 at the
point at which TCNT is to be incremented from H'1001 to H'1002.
T1
T2
P
TCNT input clock
Address
TCNT address
Internal write signal
TCNT
1001
5555
(CPU write value)
5556
Figure 11.65 Contention between TCNT Write and Increment
Rev. 3.0, 09/04, page 413 of 1086