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Under
development
Preliminary Specifications REV.B3
Specifications in this manual are tentative and subject to change.
Mitsubishi Microcomputers
M32C/83 group
SINGLE-CHIP 16/32-BIT CMOS MICROCOMPUTER
Timer A
137
(1) Timer mode
In this mode, the timer counts an internally generated count source. (See Table 1.14.1.) Figure 1.14.7
shows the timer Ai mode register in timer mode.
Table 1.14.1. Specifications of timer mode
Item
Specification
Count source
f1, f8, f2n, fC32
Count operation
Down count
When the timer underflows, it reloads the reload register contents before continuing
counting
Divide ratio
1/(m+1) m : Set value
Count start condition
Count start flag is set (= 1)
Count stop condition
Count start flag is reset (= 0)
Interrupt request generation timing When the timer underflows
TAiIN pin function
Programmable I/O port or gate input
TAiOUT pin function
Programmable I/O port or pulse output (Setting by corresponding function select
registers A, B and C)
Read from timer
Count value can be read out by reading timer Ai register
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 progress
When a value is written to timer Ai register, it is written to only reload register
(Transferred to counter at next reload time)
Select function
Gate function
Counting can be started and stopped by the TAiIN pin’s input signal
Pulse output function
Each time the timer underflows, the TAiOUT pin’s polarity is reversed
Figure 1.14.7. Timer Ai mode register in timer mode
Timer Ai mode register (i = 0 to 4) (Timer mode)
Symbol
Address
When reset
TAiMR(i=0 to 4)
035616, 035716, 035816, 035916, 035A16
00000X002
Bit name
Function
Bit symbol
W
R
b7
b6
b5
b4
b3
b2
b1
b0
0 0 : Timer mode
b1 b0
TCK1
MR3
MR2
MR1
TMOD1
MR0
TMOD0
TCK0
Count source
select bit
Operation mode
select bit
This bit is invalid in M32C/80 series.
Port output control is set by the function select
registers A, B and C.
Note 1: X value can be “0” or “1”.
Note 2: Set the corresponding function select register A to I/O port, and port direction register to “0”.
Note 3: n = 0 to 15. n is set by the count source prescaler register (address 035F16).
Gate function
select bit
0 X : Gate function not available
(TAiIN pin is a normal port pin)
1 0 : Timer counts only when TAiIN
pin is held “L”
1 1 : Timer counts only when TAiIN
pin is held “H”
0 (Set to “0” in timer mode)
(Note 2)
(Note 1)
(Note 3)
b4 b3
0 0 : f1
0 1 : f8
1 0 : f2n
1 1 : fC32
b7 b6