Mitsubishi microcomputers
M16C / 6N0 / 6N1 Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
97
Item
Specification
Count source
Count operation
The timer counts down (operating as an 8-bit or a 16-bit pulse width modulator)
The timer reloads a new count at a rising edge of PWM pulse and continues counting
The timer is not affected by a trigger that occurs when counting
High level width
n / fi
n : Set value
16-bit PWM
Cycle time
(2
16-1) / fi fixed
8-bit PWM
High level width n
(m+1) / fi
n : values set to timer Ai register’s high-order address
Cycle time
(2
8-1) (m+1) / fi
m : values set to timer Ai register’s low-order address
External trigger is input
Count start condition
The timer overflows
The count start flag is set (= "1")
The count start flag is reset (= "0")
Count stop condition
Interrupt request
generation timing
PWM pulse goes "L"
TAiIN pin function
TAiOUT pin function
Read from timer
f2, f8, f32, fC32
Programmable I/O port or trigger input
Pulse output
When timer Ai register is read, it indicates an indeterminate value
Write to timer
When counting stopped
When a value is written to timer Ai register, it is written to both reload
register and counter
When counting in progressWhen a value is written to timer Ai register, it is
written to only reload register
(Transferred to counter at next reload time)
1 1 : PWM mode
MR3
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
0: Falling edge of TAiIN pin’s input signal (Note 2)
1: Rising edge of TAiIN pin’s input signal (Note 2)
0: Count start flag is valid
1: Selected by event/trigger select register
Bit name
Timer Ai mode register
Symbol
Address
When reset
TAiMR(i = 0 to 4) 039616 to 039A16
0016
Function
Bit symbol
b7
b6
b5
b4
b3
b2
b1
b0
Operation mode select bit
b1 b0
TMOD1
TMOD0
MR0
MR2
MR1
0 0 : f2
0 1 : f8
1 0 : f32
1 1 : fC32
b7 b6
TCK1
TCK0
Count source select bit
1
11
Trigger select bit
External trigger select
bit (Note 1)
W
R
Note 1: Valid only when the TAiIN pin is selected by the event/trigger select bit (addresses
038216 and 038316). If timer overflow is selected, this bit can be "1" or "0".
Note 2: Set the corresponding port direction register to "0".
Timer A
(4) Pulse width modulation (PWM) mode
In this mode, the timer outputs pulses of a given width in succession. (See Table 1.14.5.) In this mode, the counter
functions as either a 16-bit pulse width modulator or an 8-bit pulse width modulator. Figure 1.14.11 shows the timer
Ai mode register in pulse width modulation mode. Figure 1.14.12 shows the example of how a 16-bit pulse width
modulator operates. Figure 1.14.13 shows the example of how an 8-bit pulse width modulator operates.
Table 1.14.5. Timer specifications in pulse width modulation mode
Figure 1.14.11. Timer Ai mode register in pulse width modulation mode