electroRF
Member
Hi,
I have a question on the following circuit below (taken from https://www.maximintegrated.com/app-notes/index.mvp/id/3947)
It says there that for this circuit to work, the following conditions must be satisfied - it is condition #2 that I don't understand.
Could you please help me understand condition #2?
1. For daisy-chaining to work successfully, the slave must be able to input a command at DIN during a given command-cycle (defined by the number of clock pulses required to clock in one command), and output the same command at DOUT during the subsequent command-cycle. Stated simply, there is a DIN-to-DOUT delay of one command-cycle.
2. The slave must, moreover, only execute the command written to it on the rising edge of active-low CS.
This means that as long as active-low CS remains low, the slave ignores the command and outputs it at DOUT on the following command-cycle.
If active-low CS goes high after a given command-cycle, all slaves execute the commands just written to their respective DIN inputs.
If active-low CS goes high, data is not output at DOUT.
This process makes it possible for every slave in the chain to execute a different command.
* As long as these daisy-chain requirements are satisfied, the microcontroller only needs three signals (active-low SS, SCK, and MOSI) to control all the slaves in the network.
Thank you very much!
I have a question on the following circuit below (taken from https://www.maximintegrated.com/app-notes/index.mvp/id/3947)
It says there that for this circuit to work, the following conditions must be satisfied - it is condition #2 that I don't understand.
Could you please help me understand condition #2?
1. For daisy-chaining to work successfully, the slave must be able to input a command at DIN during a given command-cycle (defined by the number of clock pulses required to clock in one command), and output the same command at DOUT during the subsequent command-cycle. Stated simply, there is a DIN-to-DOUT delay of one command-cycle.
2. The slave must, moreover, only execute the command written to it on the rising edge of active-low CS.
This means that as long as active-low CS remains low, the slave ignores the command and outputs it at DOUT on the following command-cycle.
If active-low CS goes high after a given command-cycle, all slaves execute the commands just written to their respective DIN inputs.
If active-low CS goes high, data is not output at DOUT.
This process makes it possible for every slave in the chain to execute a different command.
* As long as these daisy-chain requirements are satisfied, the microcontroller only needs three signals (active-low SS, SCK, and MOSI) to control all the slaves in the network.
Thank you very much!