M16C26 Datasheet, PDF (84/239 Pages) Renesas Technology Corp – 16-BIT CMOS SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/20 SERIES

Udenvdeelropment
Timer A
Preliminary Specifications Rev. 0.9
Specifications in this manual are tentative and subject to change. _{M16C/26 Group}
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
Timer A
Figure 1.12.3 shows the block diagram of timer A. Figures 1.12.4 to 1.12.6 show the timer A-related
registers.
Except in event counter mode, timers A0 through A4 all have the same function. Use the timer Ai mode
register (i = 0 to 4) bits 0 and 1 to choose the desired mode.
Timer A has the four operation modes listed as follows:
• Timer mode: The timer counts an internal count source.
• Event counter mode: The timer counts pulses from an external source or a timer over flow.
• One-shot timer mode: The timer stops counting when the count reaches “000016”.
• Pulse width modulation (PWM) mode: The timer outputs pulses of a given width.
Clock source
selection
f1 or f2
f8
f32
fC32
ÄTimer
ÄOne shot
ÄPWM
Clock selection
ÄTimer
(gate function)
Data bus high-order bits
Data bus low-order bits
Low-order
8 bits
Reload register (16)
High-order
8 bits
Polarity
selection
TAiIN
(i = 0 to 4)
ÄEvent counter
Clock selection
Count start flag
(Address 038016)
TB2 overflow
TAj overflow
(j = i 1. Note, however, that j = 4 when i = 0)
TAk overflow
(k = i + 1. Note, however, that k = 0 when i = 4)
To external
trigger circuit
Down count
Up/down flag
(Address 038416)
Counter (16)
Up count/down count
Always down count except
in event counter mode
TAi
Timer A0
Timer A1
Timer A2
Timer A3
Timer A4
Addresses
038716 038616
038916 038816
038B16 038A16
038D16 038C16
038F16 038E16
TAj
Timer A4
Timer A0
Timer A1
Timer A2
Timer A3
TAk
Timer A1
Timer A2
Timer A3
Timer A4
Timer A0
TAiOUT
(i = 0 to 4)
Pulse output
Toggle flip-flop
Figure 1.12.3. Block diagram of timer A
Timer Ai mode register
b7 b6 b5 b4 b3 b2 b1 b0
Symbol
TAiMR(i=0 to 4)
Address
When reset
039616 to 039A16 0016
Bit symbol
TMOD0
TMOD1
Bit name
Operation mode select bit
Function
b1 b0
0 0 : Timer mode
0 1 : Event counter mode
1 0 : One-shot timer mode
1 1 : Pulse width modulation
(PWM) mode
MR0
Function varies with each operation mode
MR1
MR2
MR3
TCK0
TCK1
Count source select bit
(Function varies with each operation mode)
RW
Figure 1.12.4. Timer A-related registers (1)
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Renesas Technology Corp.