M16C62N Datasheet, PDF (74/213 Pages) Renesas Technology Corp – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER

Timer A
Mitsubishi microcomputers
M16C / 62N Group (80-pin)
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
(1) Timer mode
In this mode, the timer counts an internally generated count source. (See Table 1.13.1.) Figure 1.13.7
shows the timer Ai mode register in timer mode.
Table 1.13.1. Specifications of timer mode
Item
Specification
Count source
f1, f8, f32, fC32
Count operation
• Down count
• 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 When the timer underflows
TAiIN pin function
Programmable I/O port or gate input
TAiOUT pin function
Programmable I/O port or pulse output
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
Note: Timer A1 and A2 do not have I/O port (TAiIN and TAiOUT).
Timer Ai mode register
b7 b6 b5 b4 b3 b2 b1 b0
0
00
Symbol
TAiMR(i=0 to 4)
Address
When reset
039616 to 039A16 0016
Bit symbol
Bit name
Function
RW
TMOD0
TMOD1
MR0
MR1
MR2
Operation mode
select bit
b1 b0
0 0 : Timer mode
Pulse output function
0 : Pulse is not output
select bit
(Note 4) ^{(TAiOUT pin is a normal port pin)}
1 : Pulse is output (Note 1)
(TAiOUT pin is a pulse output pin)
Gate function select bit
b4 b3
0 X (Note 2): Gate function not available
(Note 4)
(TAiIN pin is a normal port pin)
1 0 : Timer counts only when TAiIN pin is
held “L” (Note 3)
1 1 : Timer counts only when TAiIN pin is
held “H” (Note 3)
MR3
TCK0
TCK1
0 (Must always be “0” in timer mode)
Count source select bit
b7 b6
0 0 : f1
0 1 : f8
1 0 : f32
1 1 : fC32
Note 1: The settings of the corresponding port register and port direction register
are invalid.
Note 2: The bit can be “0” or “1”.
Note 3: Set the corresponding port direction register to “0”.
Note 4: Set these bits to “0” in timer A1 and A2 mode registers.
Figure 1.13.7. Timer Ai mode register in timer mode
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