FUJITSU F2MC-8L F202RA - Manual (Page 223)

207
CHAPTER 9 12-BIT PPG TIMER
If the set "H" width is equal to or greater than the set cycle period, "H" level outputs occur.
■ 12-bit PPG Function
The timer’s programmable pulse output generator function can be used as a 12-bit PPG because it can set a
cycle period and "H" pulse width of output pulse waveforms separately. A range of controllable duty cycles
is 0.02% to 100%. However, the smaller the compare value for the cycle period, the lower the resolution
(the greater a minimum-step duty cycle).
If the compare value for the cycle period is "2", a comparative setting of "H" pulse width is 1 or 2 (a duty
cycle of 50% or 100%) and the resolution is 1/2.
An output frequency and a duty cycle can be calculated using the following equations:
Output pulse cycle period = Compare value for cycle period
× Count clock cycle period
Duty cycle = Compare value for "H" width/Compare value
× 100(%)
Table 9.1-2 lists available resolution values, minimum-step duty cycles, and output pulse cycle periods.
=10
Ч
2
Ч
0. 3 2
µ
s
Cycle period = Comp a re v a l u e for cycle period
×
Co u nt clock cycle period
= 011110 H ( 3 0-clock period)
Ч
2
Ч
4/F CH
= 3 0
Ч
2
Ч
0. 3 2
µ
s = 19.2
µ
s
"H" width = Comp a re v a l u e for "H" width
×
Co u nt clock cycle period
= 001010 B (10-clock width)
Ч
2
Ч
4/F
CH
=6.4
µ
s
Table 9.1-2 Resolutions and Output Pulse Cycle Periods Supported when the Timer is Used as a 12-bit
PPG (1/2)
Compare
value for
cycle
period
Range of
available
compare
values for
"H" width
Output pulse cycle period
Resolution
Minimum-
step duty
cycle
Count clock
= 2 t
INST
Count clock
= 4 t
INST
Count clock
= 16 t
INST
Count clock
= 256 t
INST
0 -
Unavailable
1 -
2 1, 2 4 t
INST
8 t
INST
32 t
INST
512 t
INST 1/2 50.0%
3 1 to 3 6 t
INST
12 t
INST
48 t
INST
768 t
INST 1/3 33.3%
4 1 to 4 8 t
INST
16 t
INST
64 t
INST
1024 t
INST 1/4 25.0%
5 1 to 5 10 t
INST
20 t
INST
80 t
INST
1280 t
INST 1/5 20.0%
6 1 to 6 12 t
INST
24 t
INST
96 t
INST
1536 t
INST 1/6 16.7%
7 1 to 7 14 t
INST
28 t
INST
112 t
INST
1792 t
INST 1/7 14.3%
8 1 to 8 16 t
INST
32 t
INST
128 t
INST
2048 t
INST 1/8 12.5%