
Under
1-81
Specifications in this manual are tentative and subject to change
Rev. G
Timer A
MITSUBISHI MICROCOMPUTERS
M30222 Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
Table 1.29. Timer specifications in pulse width modulation mode
Fig. 1.55. Timer Ai mode register in pulse width modulation mode
Item
Specification
Count source
f1, f8, f32, fc32
Count operation
Timer counts down (operating as an 8-bit or 16-bit pulse modulator)
Timer reloads new count at a rising edge of PWM pulse and continues counting.
Timer is not affected by a trigger that occurs when counting.
16-bit PWM
High level width n/fi n: Set value
Cycle time (2
16
-1)/fi fixed
8-bit PWM
High level width n x (m + 1)/fi n: values set Timer Ai s high-order address
Cycle time (28-1) x (m+1)/fi m: values set Timer Ai s low-order address
Count start condition
External trigger is input
Timer overflows
Count start flag is set (=1)
Count stop condition
Count start flag is reset (=0)
Interrupt request
generation timing
PWM pulse goes L
TAiIN pin function
Programmable I/O port or trigger input
TAiOUT pin function
Pulse output
Read from timer
When Timer Ai register is read, it indicates an indeterminate value.
Write to timer
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).
Bit name
Timer Ai mode register
Symbol
TAiMR(i=0 to 4)
Address
When reset
00
16
0396
16
to 039A
16
Function
Bit symbol
TMOD0
b7
b6
b5
b4
b3
b2
1
b1
1
b0
1
Operation mode
select bit
1 1 : PWM mode
b1 b0
TMOD1
MR0
MR1
MR3
0 0 : f
1
0 1 : f
8
1 0 : f
32
1 1 : f
C32
b7 b6
TCK1
TCK0
Count source select bit
W
R
1 (Must always be
“
1
”
in PWM mode)
16/8-bit PWM mode
select bit
0: Functions as a 16-bit pulse width modulator
1: Functions as an 8-bit pulse width modulator
Trigger select bit
External trigger select
bit (Note 1)
0: Falling edge of TAi
IN
pin's input signal (Note 2)
1: Rising edge of TAi
IN
pin's input signal (Note 2)
0: Count start flag is valid
1: Selected by event/trigger select register
Note 1: Valid only when the TA
iIN
pin is selected by the event/trigger select bit
(addresses 0382
16
and 0383
16
). If timer overflow is selected, this bit can be
“
1
”
or
“
0
”
.
Note 2: Set the corresponding port direction register to "0".
MR2