Renesas M16C FAMILY series Hardware Manual page 126

M 1 6 C 2 / 8 G o r u p ( M 1 6 C
Table 12.3 Specifications in Event Counter Mode
(when processing two-phase pulse signal with timers A2, A3 and A4)
Item
Count source
Count operation
Divide ratio
Count start condition
Count stop condition
Interrupt request generation timing
TAi pin function
IN
TAi pin function
OUT
Read from timer
Write to timer
Select function (Note)
Notes:
1. Only timer A3 is selectable. Timer A2 is fixed to normal processing operation, and timer A4 is fixed to
multiply-by-4 processing operation.
R e . v 2 0 . 0 J a . n 3 , 1 2 0 0 7
R E J 0 9 B 0 0 4 7 0 - 2 0 0
2 / , 8 M 1 6 C 2 / 8 ) B
• Two-phase pulse signals input to TAi
• Increment or down-count can be selected by two-phase pulse signal
• When the timer overflows or underflows, it reloads the reload register con-
tents and continues counting. When operating in free-running mode, the
timer continues counting without reloading.
1/ (FFFF - n + 1) for increment
16
1/ (n + 1) for down-count
Set TAiS bit in the TABSR register to "1" (start counting)
Set TAiS bit to "0" (stop counting)
Timer overflow or underflow
Two-phase pulse input
Two-phase pulse input
Count value can be read by reading timer A2, A3 or A4 register
• When not counting and until the 1st count source is input after counting start
Value written to TAi register is written to both reload register and counter
• When counting (after 1st count source input)
Value written to TAi register is written to reload register
(Transferred to counter when reloaded next)
• Normal processing operation (timer A2 and timer A3)
The timer counts up rising edges or counts down falling edges on TAj
when input signals on TAj
TAj
OUT
TAj
IN
(j=2,3)
• Multiply-by-4 processing operation (timer A3 and timer A4)
If the phase relationship is such that TAk
input signal on TAk
edges on TAk
TAk pin goes "L" when the input signal on TAk
IN
counts down rising and falling edges on TAk
TAk
OUT
TAk
IN
(k=3,4)
• Counter initialization by Z-phase input (timer A3)
The timer count value is initialized to 0 by Z-phase input.
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f o 3 8 5
Specification
IN
n : set value of TAi register
pin is "H".
OUT
Increment Increment Increment Decrement
pin is "H", the timer counts up rising and falling
OUT
and TAk pins. If the phase relationship is such that
OUT IN
all edges
Increment
all edges
Increment
or TAi pins (i = 2 to 4)
OUT
0000
16
Decrement Decrement
(k=3, 4) pin goes "H" when the
IN
pin is "H", the timer
OUT
and TAk pins.
OUT IN
all edges
Decrement
all edges
Decrement
12. Timer
to FFFF
16
pin
IN