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Combinational circuit with RF Module

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blach100

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Hi

is it possible to interface a Combinational circuit with a RF module?

most of the module uses SPI, which means I need to have a clock in my circuit, which in the case of Combinational circuit is not available.

thanks in advance
 

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Hi

is it possible to interface a Combinational circuit with a RF module?

most of the module uses SPI, which means I need to have a clock in my circuit, which in the case of Combinational circuit is not available.

thanks in advance

Your question is very poorly written. I think you are asking if you can make a combinational SPI interface to communicate with an RF module that has a SPI interface.

No, SPI requires a clock (SCLK) along with other signals that have timing relationships to that clock. If you don't have any clocks then you need to start over with the architectural design.
 

dehati

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You may like to check existing SPI code ( in verilog or VHDL as the case may be) and see how you can use it to interface with the RF nodule. SPI interface comes under sequential circuits and a combinational only device will not work.
 

blach100

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You may like to check existing SPI code ( in verilog or VHDL as the case may be) and see how you can use it to interface with the RF nodule. SPI interface comes under sequential circuits and a combinational only device will not work.


yes I'm also trying to add a flipflop at the end of the combinational circuit so I can use the CLK to work with SPI
 

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SPI is NOT a combinational circuit. Adding a register at the end isn't going to work.

I'm almost certain you are writing HDL "software" as opposed to something decribing hardware.

Go look at the SPI code on Opencores as an example it uses a lot of flip-flops.
 

blach100

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SPI is NOT a combinational circuit. Adding a register at the end isn't going to work.

I'm almost certain you are writing HDL "software" as opposed to something decribing hardware.

Go look at the SPI code on Opencores as an example it uses a lot of flip-flops.

yes I got your idea, what I'm planing to design is a circuit that is connected to an RF transceiver, and that acts like a mirror. which means when RF module receives a signal, the circuit must compare it to a stored signal, then send back the same signal. I want it to be fast that's why I chose it to be combinationnal, I don't want to use any clock that would create a delay for me, but I came to realize that most of the RF module have SPI as an interface, so I must use the clock.
if I insert the SPI code (from opencores) that has a lot of Flip-Flops that would really decrease the speed of my intended application.
 

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I question the premise that the RF module uses SPI to transmit or receive data.
SPI is typically used as the control interface not as a data link.
 

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