7220 Datasheet, PDF (94/303 Pages) Renesas Technology Corp – 8-BIT SINGLE-CHIP MICROCOMPUTER

FUNCTIONAL DESCRIPTION
2.10 PWM
2.10.3 8-bit PWM (PWM0 to PWM5: address 00D016 to 00D416 and 00F616 )
The 8-bit PWM outputs waveform which is the logical sum (OR) of pulses corresponding to bits 0 to 7 of
the 8-bit PWM register.
That is to say, 8 kinds of pulses corresponding to the weight of each bit of the 8-bit PWM register are
output inside the circuit during 1 cycle. Among these pulses, OR of pulses that correspond to bits, which
is set to “1,” in the 8-bit PWM register to external devices as PWM output.
Figure 2.10.4 shows the pulse waveforms corresponding to the weight of each bit of the 8-bit PWM register.
Figure 2.10.5 shows the example of 8-bit PWM output.
As shown in the Figures, 256 kinds of output (HIGH duration: 0/256 to 255/256) are selected by changing
the contents of the PWM register (a length of entirely HIGH cannot be output).
7220 Group User’s Manual
2-67