M30222 Datasheet, PDF (86/237 Pages) Mitsubishi Electric Semiconductor – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER

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Specifications in this manual are tentative and subject to change
MITSUBISHI MICROCOMPUTERS
M30222 Group
Rev. G
Timer B
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
(1) Timer mode
In this mode, the timer counts an internally generated count source. (See Table 1.30).
Figure 1.64 shows the Timer Bi mode register in timer mode.
Usage Precaution
Reading the Timer Bi register while a count is in progress allows reading , with arbitrary timing, the value of
the counter. Reading the Timer Bi register with the reload timing gets “FFFF16”. Reading the Timer Bi
register after setting a value in the Timer Bi register with a count halted but before the counter starts counting
gets a proper value.
Table 1.30. Timer mode specifications
Item
Count source
Count operation
Divide ratio
Count start condition
Count stop condition
Interrupt request generation timing
TBiIN pin function
Read from timer
Write to timer
Specification
f1, f8, f32, fc32
Count down
When the timer underflows, it reloads the reload register contents before continuous counting
1/(n+1)
n: Set value
Count start flag is set (=1)
Count start is reset (=0)
When the timer underflows
Programmable I/O port or gate input
Count value can be read out by reading Timer Bi register
When counting stopped
When a value is written to Timer Bi register, it is written to both reload register and counter
When the timer underflows, it reloads the reload register contents before continuous counting
When a value is written to Timer Bi register,it is written to only reload register
(Transferred to counter at next reload time)
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