3 pulse width modulator output wave example, Pulse width modulator output wave example -43, Basic pulse width waveform -43 – Intel PXA255 User Manual
Page 147: Pwm_pervaln bit definitions -43, Figure 4-4
Intel® PXA255 Processor Developer’s Manual
4-43
System Integration Unit
4.5.3
Pulse Width Modulator Output Wave Example
is an example of the output of a Pulse Width Modulator for reference.
PWM_PERVAL[PV] = 0xA
PWM_DUTY[FDCYCLE] = 0x0
PWM_DUTY[DCYCLE] = 0x6
PWM_CTRL[PRESCALE] = 0x0
is created by writing PWM_PERVALn[PV] with a decimal
value of 10 (11 clocks) and PWM_DUTYn[DCYCLE] with 6.
also shows that
PWM_CTRLn[PRESCALE] is configured with a value of 0x0 loaded, which results in the
PSCLK_PWMn having the same frequency as the 3.6864 MHz input clock.
Table 4-48. PWM_PERVALn Bit Definitions
Physical Address
0x40B0_0008
0x40C0_0008
PWM Period Control Registers
(PWM_PERVAL0, PWM_PERVAL1)
System Integration Unit
Bit
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9
8
7
6
5
4
3
2
1
0
reserved
PV
Reset 0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
Bits
Name
Description
<31:10>
—
reserved
<9:0>
PV
PWMn Period Control:
The number of PSCLK_PWMn cycles that comprise one PWM_OUTn cycle
NOTE: If PV = 0x0, the PWMn clock (PWM_OUTn) is set high and does not toggle unless
FDCYCLE=0x0 and DCYCLE=0x0. In this case PWM_OUTn is set low and does
not toggle regardless of the value in PV.
Figure 4-4. Basic Pulse Width Waveform
PWM_OUTn
PSCLK_PWMn
PWM_DUTYn = 6
PWM_PERVALn = 10 (+1)
3.6864 MHz