In the normal mode, the user can place an edge of PWM channel only at points aligned with peripheral clock edge. This limits the number of bits of resolution that the user is allowed in controlling the duty. In reality the user may need to place an edge that is delayed from the zero-duty mark by a time interval, say 0.7 Tsclk. The High-Precision feature allows a fine-grained edge placement within the system clock period as shown in the figure below leading to a very high resolution in placing the edge of PWM signal.
The High-Precision Edge Placement feature in PWM allows the user to specify such Fractional Duty Cycles as 0.7, by providing additional duty register bits to the, which are contained in the PWM_HPxHy registers. The High-Precision feature is available only for High-side output of each channel.