SCPS286 July 2025 TPLD2001
ADVANCE INFORMATION
When configured as a One-shot, this macro-cell generates a pulse that begins when a valid edge appears on the IN input, which triggers the counter to begin counting down from DATA following two CLK cycles, and the pulse ends once the counter reaches 0 and DATA is subsequently reloaded into the counter and waiting for the next trigger. Triggers received while the counter is decrementing are ignored. The initial output value of this macro-cell after device startup can also be configured to Bypass Initial, Initial Low, or Initial High. The edge on which the One-shot is reset is determined by the Edge select parameter and can be configured as:
Rising: only rising edges of IN reset the one-shot.
Falling: only falling edges of IN reset the one-shot.
Both: both rising and falling edges of IN reset the one-shot.
An additional 2 clock cycles are included in the one-shot pulse width calulation for clock synchronization.
The pulse width of the one-shot is calculated by ONESHOT = (DATA + 3)/fCLK.
Figure 7-18 shows an example of how the One-shot macro-cell operates with respect to the Edge select parameter.