M30222 Datasheet, PDF (73/237 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
(1) Timer mode
In this mode, the timer counts an internally generated count source. (See Table 1.25.) Figure 1.51 shows
the Timer Ai mode register in timer mode.
Usage Precautions
Reading the Timer Ai register while a count is in progress allows reading, with arbitrary timing, the value of
the counter. Reading the Timer Ai register with the reload timing gets “FFFF16”. Reading the Timer Ai register
after setting a value in theTimer Ai register with a count halted but before the counter starts counting gets a
proper value.
Table 1.25. Timer mode specifications
Item
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
Select function
Specification
f1, f8, f32, fc32
Count down
When the timer underflows, it reloads the reload register contents before count-
ing continues.
1/(n+1) n: Set value
Count start flag is set (=1)
Count start flag is reset (=0)
When timer underflows
Programmable I/O port or gate input
Programmable I/O port or pulse output
Count value can be read out by reading Timer Ai register
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 regiser, it is written to only reload register
(Transferred to counter at next reload time).
Gate function
Counting can be started and stopped by the TAiIN pin s input signal.
Pulse output function
Each timer the timer underflows, the TAiOUT pin s polarity is reversed.
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