M30222 Datasheet, PDF (78/237 Pages) Mitsubishi Electric Semiconductor – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER

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MITSUBISHI MICROCOMPUTERS
Specifications in this manual are tentative and subject to change
M30222 Group
Rev. G
Timer A
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
(3) One-shot timer mode
In this mode, the timer operates only once as shown in Table 1.28. When a trigger occurs, the timer
starts up and continues operating for a given period. Figure 1.54 shows the Timer Ai mode register in
one-shot timer mode.
Usage Precautions
(1) Setting the count start flag to “0” while a count is in progress causes as follows:
• The counter stops counting and a content of reload register is reloaded.
• The TAiOUT pin outputs “L” level.
• The interrupt request generated and the Timer Ai interrupt request bit goes to “1”.
(2) The Timer Ai interrupt request bit goes to “1” if the timer's operation mode is set using any of the following
procedures:
• Selecting one-shot timer mode after reset.
• Changing operation mode from timer mode to one-shot timer mode.
• Changing operation mode from event counter mode to one-shot timer mode.
Therefore, to useTimer Ai interrupt (interrupt request bit), set Timer Ai interrupt request bit to “0” after the
above listed changes have been made.
Table 1.28. Timer specifications in one-shot timer mode
Item
Specification
Count source
Count operation
Divide ratio
Count start condition
Count stop condition
Interrupt request
generation timing
TAiIN pin function
TAiOUT pin function
Read from timer
Write to timer
f1, f8, f32, fc32
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.
1/n
n: Set value
An external trigger is input
Timer overflows
One-shot start flag is set (=1)
A new count is reloaded after the count has reached 0000₁₆
The count start flag is reset (=0)
The count reaches 0000₁₆
Programmable I/O port or trigger input
Programmable I/O port or pulse output
When Timer Ai register is read, it indicates an indeterminate value.
When counting stops
When a value is written to Timer Ai register, it is written to both reload register
and counter
When counting is 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).
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