M306V5ME-XXXSP Datasheet, PDF (83/262 Pages) Mitsubishi Electric Semiconductor – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER with CLOSED CAPTION DECODER and ON-SCREEN DISPLAY CONTROLLER

MITSUBISHI MICROCOMPUTERS
M306V5ME-XXXSP
M306V5EESP
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER with CLOSED CAPTION DECODER
and ON-SCREEN DISPLAY CONTROLLER
(2) Event counter mode
In this mode, the timer counts an external signal or an internal timer’s overflow. (See Table 2.10.6) Figure
2.10.22 shows the timer Bi mode register in event counter mode.
Table 2.10.6 Timer specifications in event counter mode
Item
Specification
Count source
• External signals input to TB0IN pin
• Effective edge of count source can be a rising edge, a falling edge, or falling and
rising edges as selected by software
Count operation
• Counts down
• When the timer underflows, it reloads the reload register contents before continuing
counting
Divide ratio
1/(n+1)
n : Set value
Count start condition
Count start flag is set (= 1)
Count stop condition
Count start flag is reset (= 0)
Interrupt request generation timing The timer underflows
TB0IN pin function
Count source input
Read from timer
Count value can be read out by reading timer Bi register
Write to timer
• When counting stopped
When a value is written to timer Bi register, it is written to both reload register and counter
• When counting in progress
When a value is written to timer Bi register, it is written to only reload register
(Transferred to counter at next reload time)
Timer Bi mode register
b7 b6 b5 b4 b3 b2 b1 b0
01
Symbol
TBiMR(i=0 to 2)
Address
039B16 to 039D16
When reset
00?X00002
Bit symbol
TMOD0
TMOD1
Bit name
Function
Operation mode select bit ^{b1 b0}
0 1 : Event counter mode
MR0
MR1
Count polarity select
bit (Note 1)
b3 b2
0 0 : Counts external signal's falling
edges
0 1 : Counts external signal's rising
edges
1 0 : Counts external signal's falling
and rising edges
1 1 : Inhibited
RW
MR2
MR3
TCK0
TCK1
0 (Fixed to “0” in event counter mode; i = 0)
(Note 2)
Nothing is assigned (i = 1, 2).
In an attempt to write to this bit, write “0.” The value, if read, turns out to
be indeterminate.
(Note 3)
Invalid in timer mode.
In an attempt to write to this bit, write “0.” The value, if read in
event counter mode, turns out to be indeterminate.
Invalid in event counter mode.
Can be “0” or “1”.
Event clock select
0 : Input from TB0IN pin (Note 4)
1 : TBj overflow
(j = i – 1; however, j = 2 when i = 0)
Notes 1: Valid only when input from the TB0IN pin is selected as the event clock.
If timer's overflow is selected, this bit can be “0” or “1”.
2: Timer B0.
3: Timer B1, timer B2.
4: Set the corresponding port direction register to “0”.
Figure 2.10.22 Timer Bi mode register in event counter mode (i = 0 to 2)
Rev. 1.0
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