![](http://datasheet.mmic.net.cn/280000/M30623MAA-2MGP_datasheet_16083420/M30623MAA-2MGP_77.png)
Mitsubishi microcomputers
M16C / 62A Group (80-pin)
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
Timer A
77
Item
Specification
Count source
Count operation
f
1
, f
8
, f
32
, f
C32
The timer counts down
When the count reaches 0000
16
, the timer stops counting after reloading a new count
If a trigger occurs when counting, the timer reloads a new count and restarts counting
1/n n : Set value
An external trigger is input
The timer overflows
The one-shot start flag is set (= 1)
A new count is reloaded after the count has reached 0000
16
The count start flag is reset (= 0)
Interrupt request generation timing
The count reaches 0000
16
TAi
IN
pin function
Programmable I/O port or trigger input
TAi
OUT
pin function
Programmable I/O port or pulse output
Read from timer
When timer Ai register is read, it indicates an indeterminate value
Write to timer
When counting stopped
When a value is written to timer Ai register, it is written to both reload
register and counter
When counting in progress
When a value is written to timer Ai register, it is written to only reload register
(Transferred to counter at next reload time)
Note: Timer A1 and A2 do not have I/O port (TAi
IN
and TAi
OUT
).
Divide ratio
Count start condition
Count stop condition
Table1.13.4. Timer specifications in one-shot timer mode
Figure 1.13.10. Timer Ai mode register in one-shot timer mode
(3) One-shot timer mode
In this mode, the timer operates only once. (See Table 1.13.4.) When a trigger occurs, the timer starts up and
continues operating for a given period. Figure 1.13.10 shows the timer Ai mode register in one-shot timer mode.
Bit name
Timer Ai mode register
Symbol
TAiMR(i = 0 to 4) 0396
16
to 039A
16
Address
When reset
00
16
Function
Bit symbol
TMOD0
b7
b6
b5
0
b4
b3
b2
b1
1 0
b0
Operation mode select bit
1 0 : One-shot timer mode
b1 b0
TMOD1
MR0
Pulse output function
select bit
0 : Pulse is not output
(TA
iOUT
pin is a normal port pin)
1 : Pulse is output (Note 1)
(TAi
OUT
pin is a pulse output pin)
MR2
MR1
MR3
0 (Must always be “0” in one-shot timer mode)
0 0 : f
1
0 1 : f
8
1 0 : f
32
1 1 : f
C32
b7 b6
TCK1
TCK0
Count source select bit
0 : One-shot start flag is valid
1 : Selected by event/trigger select
register
Trigger select bit
External trigger select
bit (Note 2,4)
0 : Falling edge of TAi
IN
pin's input signal (Note 3)
1 : Rising edge of TAi
IN
pin's input signal (Note 3)
Note 1: The settings of the corresponding port register and port direction register are invalid.
Note 2: Valid only when the TA
iIN
pin is selected by the event/trigger select bit
(addresses 0382
16
and 0383
16
). If timer overflow is selected, this bit can be “1” or “0”.
Note 3: Set the corresponding port direction register to “0”.
Note 4: Set these bits "0" in timer A1 and A2 mode registers.
W
R
AA
AA
AA
AA
AA
AA
AA
AA
AA
A
(Note 4)