Minimum pulse width to wakeup PSoC5 from sleep via PICU

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mafi
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Dear Community,

i got a sensor with an undefined pulse width, and i'm unsure if i have to stretch the pulse via hardware, so the PSoC5 will trigger an interrupt and wakup from sleep mode.

In the Datasheet for the Interrupt Component "cy_isr_v1_71.pdf" is mentioned that a pulse is converted to a period of "bus_clk". Is this also true for signals shorter than bus_clk?

Best regards,

Matthias

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Rakesh_Patrudu
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25 solutions authored 5 likes given 50 replies posted

Hi @mafi ,

The Interrupt Component's datasheet "cy_isr_v1_71.pdf" mentions that a pulse is converted to a period of "bus_clk". This means that the component expects a signal with a minimum duration of one clock cycle of the bus_clk. If the signal duration is shorter than the bus_clk, the component may not detect it as a valid interrupt event.
So, signals shorter than the bus_clk can be used as interrupt sources, but they need to have a duration of at least one clock cycle of the bus_clk for the interrupt component to detect them.

Best regards,
Rakesh

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Rakesh_Patrudu
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25 solutions authored 5 likes given 50 replies posted

Hi @mafi ,

The Interrupt Component's datasheet "cy_isr_v1_71.pdf" mentions that a pulse is converted to a period of "bus_clk". This means that the component expects a signal with a minimum duration of one clock cycle of the bus_clk. If the signal duration is shorter than the bus_clk, the component may not detect it as a valid interrupt event.
So, signals shorter than the bus_clk can be used as interrupt sources, but they need to have a duration of at least one clock cycle of the bus_clk for the interrupt component to detect them.

Best regards,
Rakesh

@mafi 

Based on @Rakesh_Patrudu information, if you need to support a pulse width shorter than the bus_clk period, you may be able to increase the bus_clk frequency (reduce the bus_clk period) by increasing the base frequency from which the bus_clk is derived.

Len
"Engineering is an Art. The Art of Compromise."