Fujitsu FR81S Manual Do Utilizador
CHAPTER 19: BASE TIMER
5. Operation
FUJITSU SEMICONDUCTOR LIMITED
CHAPTER
: BASE TIMER
FUJITSU SEMICONDUCTOR CONFIDENTIAL
63
Output Waveform
The waveform (TOUT signal) of the 16-bit PWM timer can be output. The waveform (TOUT signal) to be
output varies according to the setting of the OSEL bit of the base timer x timer control register (BTxTMCR).
Normal polarity (OSEL = 0)
⋅
When the 16-bit PWM timer is activated: "L" level
⋅
When a duty match occurs: "H" level
⋅
When an underflow occurs: "L" level
Inverted polarity (OSEL = 1)
⋅
When the 16-bit PWM timer is activated: "H" level
⋅
When a duty match occurs: "L" level
⋅
When an underflow occurs: "H" level
The output (TOUT signal) can be fixed at the "L" or "H" level.
The output level varies depending on the setting of the OSEL bit of the base timer x timer control register
(BTxTMCR). Examples of procedures are shown below.
Figure 5-14 Examples of Procedures for Fixing to "L" and "H" Levels
0002
0001
0000
XXXX
Duty value
PWM output
waveform
Decrement duty value
PWM output
waveform
Increment duty value
Underflow interrupt request
Duty match interrupt request
"1" is set to the PMSK bit with an underflow interrupt.
The output signal will be fixed to the " L" level from the set cycle.
PMSK bit : PMSK bit of base timer x timer control register (BTxTMCR)
If the duty value is set to the cycle setting value when a duty match
interrupt request is generated, the output signal will be fixed to the
" H" level in the next cycle.
Example of procedure for fixing to "H" level (OSEL = 0)
Example of procedure for fixing to " L" level (OSEL = 0)
H
H
H
H
MB91520 Series
MN705-00010-1v0-E
696