Filter
Top Products
VIII - 9
Chapter 8 Time Base Timer / 8-bit Free-running Timer
8-bit Free-running Timer
Count Timing of Timer Operation (Timer 6)
Binary counter counts up with the selected clock source as a count clock.
(A) When any data is written to the compare register as the TM6CLRS flag is "0", the binary
counter is cleared to x'00'.
(B) Even if any data is written to the compare register as the TM6CLRS flag is "1", the binary
counter is not changed.
(C) When the binary counter reaches the value of the compare register as the TM6CLRS flag is
"1", an interrupt request flag is set at the next count clock.
(D) When an interrupt request flag is set, the binary counter is cleared to x'00' and restarts the
counting.
(E) Even if the binary counter reaches the value of the compare register as the TM6CLRS flag is
"0", no interrupt request flag is set.
Figure 8-3-2 Count Timing of Timer Operation (Timer 6)
M
NM
01
01 02 N-1
N02/00
00 01
Count clock
TM6CLRS
flag
Compare
register
Binary
counter
Interrupt
request
flag
02 03 M-1
M
00 01
(A)
(C)
(D)
(B)
(E)
If the compare register is set the smaller than the binary counter during the count operation,
the binary counter counts up to the overflow, at first.
If fx is selected as the count clock source in timer 6, when the binary counter is read at
operation, uncertain value on counting up may be read. To prevent this, select the synchro-
nous fx as the count clock source.
But if the synchronous fx is selected as the count clock source, CPU mode cannot return
from STOP/HALT mode.
When the binary counter reaches the value in the compare register, the inrerrupt request flag
is set and the binary counter is cleared, at the next count clock.
So, set the compare register as :
Compare register setting = (count till the interrupt request - 1)