Unde
Timer X
deeopmen
Mitsubishi microcomputers
M30201 Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
70
Item
Specification
Count source
Count operation
f
1
, f
8
, f
32
, f
C32
The timer counts down
When the count reaches 0000
16
, 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
The timer overflows
The one-shot start flag is set (= 1)
A new count is reloaded after the count has reached 0000
16
The count start flag is reset (= 0)
Interrupt request generation timing
The count reaches 0000
16
TXi
INOUT
pin function
Programmable I/O port, trigger input or pulse output
Read from timer
When timer Xi register is read, it indicates an indeterminate value
Write to timer
When counting stopped
When a value is written to timer Xi register, it is written to both reload
register and counter
When counting in progress
When a value is written to timer Xi register, it is written to only reload register
(Transferred to counter at next reload time)
Divide ratio
Count start condition
Count stop condition
Table 1.23. Timer specifications in one-shot timer mode
Figure 1.62. Timer Xi mode register in one-shot timer mode
(3) One-shot timer mode
In this mode, the timer operates only once. (See Table 1.23.) When a trigger occurs, the timer starts up and
continues operating for a given period. Figure 1.62 shows the timer Xi mode register in one-shot timer mode.
Bit name
Function
Bit symbol
Operation mode
select bit
pulse width measurement mode
0 : Pulse is not output
(TXi
INOOUT
pin is a normal port pin)
1 : Pulse is output (Note 1)
(TXi
INOOUT
pin is a pulse output pin)
b1 b0
TMOD1
MR0
TMOD0
Pulse output function
select bit
MR2
MR1
MR3
0 (Must always be “0” in one-shot timer mode)
0 0 : f
1
0 1 : f
8
1 0 : f
32
1 1 : f
C32
b7 b6
TCK1
TCK0
Count source select bit
1 0
0
0 : One-shot start flag is valid
1 : Selected by event/trigger select register (Note 4)
Trigger select bit
External trigger select
bit (Note 2)
0 : Falling edge of TXi
INOOUT
pin's input signal (Note 3)
1 : Rising edge of TXi
INOOUT
pin's input signal (Note 3)
W
R
AA
AA
AA
AA
AA
AA
AA
AA
AA
Note 1: Set the corresponding port direction register to “1” (output mode). External trigger cannot be selected
as count start condition when pulse output function is selected.
Note 2: Valid only when the TXi
INOUT
pin is selected by the event/trigger select bit (addresses 0383
16
). If
timer overflow is selected, this bit can be “1” or “0”.
Note 3: Set the corresponding port direction register to “0” (input mode).
Note 4: Pulse output function cannot be selected when TXi
INOUT
pin is selected by the event/trigger select bit
(addresses 0383
16
).
Timer Xi mode register
Symbol
TXiMR(i = 0 to 2) 0397
16
to 0399
16
Address
When reset
00
16
b7
b6
b5 b4
b3
b2
b1
b0