
Rev.2.00 Oct 16, 2006
page 9 of 354
REJ09B0340-0200
M30245 Group
2. Timer A
Figure 2.2.3. Timer A-related registers (2)
Function
R W
Timer Ai register (i = 0 to 4) (Note 1)
b7
b8)
(b15
b0
O O
X O
16-bit counter (set to divide ratio)
16-bit counter (set to divide ratio) (Note 2)
16-bit counter (set to one-shot width)
(Note 6)
16-bit PWM (set to PWM pulse "H" width)
(Note 4, 7)
Low-order bits: 8-bit prescaler
(set to PWM period) (Notes 5, 7)
High-order bits : 8-bit PWM
(set to PWM pulse "H" width) (Notes 5, 7)
000016 to FFFF16
Values that can be set
0016 to FE16 (Both high-order and
low-order addresses) (Note 3)
Note 1 : Read and write data in 16-bit units.
Note 2 : Counts pulses from an external source of timer overflow.
Note 3 : Use MOV instruction to write to this register.
Note 4 : When setting value is n, PWM period and “H” width of PWM pulses are:
PWM period : (216- 1)/fi
PWM pulse “H” width : n/fi
Note 5 : When setting value of high-order address is n and setting value of low-
order address is m, PWM period and “H” width of PWM pulse are:
PWM period : (28- 1) X (m + 1)/fi
PWM pulse “H” width : (m + 1)n/fi
Note 6 : When the Timer Ai register is set to “000016”, the counter does not
operate and the Timer Ai interrupt request is not generated. When the
pulse is se to output, the pulse does not output from the TAiOUT pin.
Note 7 : When the Timer Ai register is set to “000016”, the pulse width modulator
does not operate and the output level of the TAiOUT pin remains “L”
level, therefore the Timer Ai interrupt request is not generated. This also
occurs in the 8-bit pulse width modulator mode when the significant 8
high-order bits in the Timer Ai register are set to “0016”
b7
b0
Symbol
TA0
038716, 038616
Indeterminate
TA1
038916, 038816
Indeterminate
TA2
038B16, 038A16
Indeterminate
TA3
038D16, 038C16
Indeterminate
TA4
038F16, 038E16
Indeterminate
Address
When reset
(Note 3)
Timer mode
Event counter
mode
One-shot
timer mode
16-bit PWM
8-bit PWM
Mode
000016 to FFFF16
Bit Symbol
Bit Name
Function
R W
TA0S
Timer A0 count start flag
Symbol
TABSR
Address
038016
When reset
XXX000002
Count start flag
b7
b5
b6
b4
b3
b2
b1
b0
O O
TA1S
TA2S
TA3S
TA4S
O O
_ _
Timer A1 count start flag
Timer A2 count start flag
Timer A3 count start flag
Timer A4 count start flag
0 : Stops counting
1 : Starts counting
Nothing is assigned. Write “0” when writing to these bits.
The contents are indeterminate if read.