M16C26 Datasheet, PDF (94/239 Pages) Renesas Technology Corp – 16-BIT CMOS SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/20 SERIES

Udenvdeelropment
Timer B
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 B
Figure 1.13.16 shows the block diagram of timer B. Figures 1.13.17 and 1.13.18 show the timer B-related
registers.
Use the timer Bi mode register (i = 0 to 2) bits 0 and 1 to choose the desired mode.
Timer B has three 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 overflow.
• Pulse period/pulse width measuring mode: The timer measures an external signal's pulse period or
pulse width.
Data bus high-order bits
Clock source selection
f1 or f2
f8
f32
fC32
Timer
Pulse period/pulse width measurement
Clock selection
Event counter
Data bus low-order bits
Low-order 8 bits
Reload register (16)
High-order 8 bits
Counter (16)
TBiIN
(i = 0 to 2)
Polarity switching
and edge pulse
Can be selected in only
event counter mode
TBj overflow
( j = i 1. Note, however,
j = 2 when i = 0)
Count start flag
(address 038016)
Counter reset circuit
TBi
Timer B0
Timer B1
Timer B2
Address
039116 039016
039316 039216
039516 039416
TBj
Timer B2
Timer B0
Timer B1
Figure 1.13.16. Block diagram of timer B
Timer Bi mode register
b7 b6 b5 b4 b3 b2 b1 b0
Symbol
Address
TBiMR(i = 0 to 2) 039B16 to 039D16
When reset
00XX00002
Bit symbol
TMOD0
TMOD1
MR0
MR1
MR2
Bit name
Operation mode select bit
Function
b1 b0
0 0 : Timer mode
0 1 : Event counter mode
1 0 : Pulse period/pulse width
measurement mode
1 1 : Must not be set.
Function varies with each operation mode
MR3
TCK0
TCK1
Count source select bit
(Function varies with each operation mode)
Note 1: Timer B0.
Note 2: Timer B1, timer B2.
Figure 1.13.17. Timer B-related registers (1)
R
W
(Note 1)
(Note 2)
88
Renesas Technology Corp.