M16C62A Datasheet, PDF (78/242 Pages) Mitsubishi Electric Semiconductor – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER

Timer A
Mitsubishi microcomputers
M16C / 62A Group (80-pin)
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
(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.
Table1.13.4. Timer specifications in one-shot timer mode
Item
Specification
Count source
f1, f8, f32, fC32
Count operation
• The timer counts down
• When the count reaches 000016, the timer stops counting after reloading a new count
• If a trigger occurs when counting, the timer reloads a new count and restarts counting
Divide ratio
1/n n : Set value
Count start condition
• An external trigger is input
• The timer overflows
• The one-shot start flag is set (= 1)
Count stop condition
• A new count is reloaded after the count has reached 000016
• The count start flag is reset (= 0)
Interrupt request generation timing The count reaches 000016
TAiIN pin function
Programmable I/O port or trigger input
TAiOUT 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 (TAiIN and TAiOUT).
Timer Ai mode register
b7 b6 b5 b4 b3 b2 b1 b0
0
10
Symbol
Address
When reset
TAiMR(i = 0 to 4) 039616 to 039A16 0016
Bit symbol
TMOD0
TMOD1
MR0
Bit name
Function
Operation mode select bit ^{b1 b0}
1 0 : One-shot timer mode
Pulse output function 0 : Pulse is not output
select bit
(Note 4) ^{(TAiOUT pin is a normal port pin)}
1 : Pulse is output (Note 1)
(TAiOUT pin is a pulse output pin)
RW
MR1
External trigger select
bit (Note 2,4)
0 : Falling edge of TAiIN pin's input signal (Note 3)
1 : Rising edge of TAiIN pin's input signal (Note 3)
MR2
MR3
Trigger select bit
0 : One-shot start flag is valid
1 : Selected by event/trigger select bits
0 (Must always be “0” in one-shot timer mode)
TCK0
TCK1
Count source select bit
b7 b6
0 0 : f1
0 1 : f8
1 0 : f32
1 1 : fC32
Note 1: The settings of the corresponding port register and port direction register are invalid.
Note 2: Valid only when the TAiIN pin is selected by the event/trigger select bit
(addresses 038216 and 038316). 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 to “0” in timer A1 and A2 mode registers.
Figure 1.13.10. Timer Ai mode register in one-shot timer mode
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