Timer Functions - The HCS12/9S12: An Introduction to Software and Hardware Interfacing - page 424

PP0Lx = 0

PP0Lx = 1

PWMDTYx PWMDTYx

PWMPERx PWMPERx

Period = PWMPERx * 2

Figure 8.48 ■ PWM center-aligned output waveform

Clock source 7

High Low

PWMCNT6 PWMCNT7

Period/Duty compare PWM7

Clock source 5

Low

High

PWMCNT5

PWMCNT4

Period/Duty compare PWM5

Clock source 3

High Low

PWMCNT2 PWMCNT3

PWM3

Period/Duty compare

Clock source 1

High

Low

PWMCNT1

PWMCNT0

Period/Duty compare PWM1

Figure 8.49 ■ PWM 16-bit mode

When PWM channels k and k 1 1 are concatenated, channel k is the high-order channel,
whereas channel k 1 1 is the low-order channel. When using the 16-bit concatenated mode, the
clock source is determined by the low-order 8-bit channel clock select control bits. That is, it is
determined by channel k 1 1 ( k 5 0, 2, 4, or 6) when channel k and k 1 1 are concatenated. The
resulting PWM is output to the pin of the corresponding low-order 8-bit channel. The polarity