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CHAPTER 7 8-BIT TIMERS A0, B0
User’s Manual U15798EJ2V0UD
(2) 8-bit timer mode control register B0 (TMCB0)
8-bit timer mode control register B0 (TMCB0) is used to control the timer B0 count clock setting and the operation
mode setting.
TMCB0 is set by a 1-bit or 8-bit memory manipulation instruction.
RESET input sets TMCB0 to 00H.
Figure 7-5. Format of 8-Bit Timer Mode Control Register B0
Symbol
7
6
5
4
3
2
1
0
Address
After reset
R/W
TMCB0
TCEB0
0
TCLB02 TCLB01 TCLB00 TMDB01 TMDB00 TOEB0
FF6EH
00H
R/W
TCEB0
Control of TMB0 count operation
Note 1
0
Clears TMB0 count value and stops operation (the count value is also cleared for TMA0 during
cascade connection mode)
1
Starts count operation (the count operation is also started for TMA0 during cascade connection mode)
TCLB02 TCLB01 TCLB00
Selection of timer B0 count clock
0
0
0
f
X
/2
2
(2.5 MHz)
0
0
1
f
X
/2
3
(1.25 MHz)
0
1
0
f
TMI
0
1
1
f
TMI
/2
1
0
0
f
TMI
/2
2
1
0
1
f
TMI
/2
3
Other than above
Setting prohibited
TMDA00 TMDB01 TMDB00
Selection of operation mode for timer A0 and timer B0
Note 2
0
0
0
8-bit timer counter mode (discrete mode)
1
0
1
16-bit timer counter mode (cascade connection mode)
0
1
1
Carrier generator mode
0
1
0
Timer B0: PWM output mode
Timer A0: 8-bit timer counter mode
Other than above
Setting prohibited
TOEB0
Control of timer output
0
Output disabled (port mode)
1
Output enabled
Notes
1.
Since the count operation is controlled by TCEB0 in cascade connection mode, any setting for TCEA0
(bit 7 of TMCA0) is ignored.
2.
The operation mode selection is set to both the TMCA0 register and TMCB0 register.
Remarks 1.
f
X
: Main system clock oscillation frequency
2.
f
TMI
: Input frequency from TMIB0 pin
3.
The parenthesized values apply to operation at f
X
= 10.0 MHz.
Содержание mPD780344 Series
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