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PSoC™ 6 Forum Discussions

AyKo_4382201
Level 2
10 replies posted 5 replies posted 5 questions asked
Level 2

Hi,

I'm using ADC component of CYBLE-416045-02 MCU. I have 4 analog pins which needs to be attached on 4 separate ADC channels but its showing me analog internal routing error. For the time being I'm using an internal mux like shown in the picture, but i want to use 4 different  channels of the ADC and not through internal mux.Please help.

AyKo_4382201_0-1611206982527.png

AyKo_4382201_1-1611207267158.png

 

 

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Vison_Zhang
Moderator
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Moderator

If  you use external AMUX component, that's ok. If you use the sar sequencer mux inside SARADC component, PORT10 is the must choice.

See below picture,  the sar sequencer mux inside SARADC component only controls the switches surround by red circle, the analog route connects these switches can only routed to PORT10 directly.  So if you have made the PCB board, you should use external AMUX component instead of sar sequencer mux.

 

Capture.PNG

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Vasanth
Moderator
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Moderator

Hi,

When you are using different channels inside the ADC, SAR Sequencer block takes care of the ADC conversion process(From swithcing the input to storing the result) without the intervention of the CPU. But there are limitations on the resource routability in this case. At a time only 2 Amux bus can be used as it is a limited resource. You can try giving port 10 pins as input and see whether the routing is getting successful. Also make sure that Analog mux bus is used by some other resource(eg IDAC or some other resource). Also you can refer I/O pin selection section in this appnote.

Best Regards,
Vasanth

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AyKo_4382201
Level 2
10 replies posted 5 replies posted 5 questions asked
Level 2

Hi,

I think there's some confusion between us. We want to eliminate the use of internal AMux component and use 4 different ADC channels. When we do this by attaching 4 analog inputs to these 4 channels, we are getting this internal routing error. Can you tell me how can I remove this error and use 4 ADC channels? 

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Vison_Zhang
Moderator
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Moderator

I think the root cause is you locked the analog pin VIN and SHIFT_BACK to P5[2] and P0[1] respectively.  If you check the analog tab of .cydwr you will find the analog routing diagram of silicon. PORT10 is the dedicate ADC input pin, if you choose pins in PORT10 as analog input pin, the analog route will connect directly without occupy the global AMUXA and AMUXB, but you choose to use P5[2] and P0[1],  so AMUXA or(and) AMUXB will be occupied to build the anlog routing from pin to ADC, if there has  other Analog component like CapSense also need to use AMUXA/AMUXB, they analog routing conflict occur.

 

If you have not decide which pin to use as ADC analog input pin,  you should use PORT10.

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AyKo_4382201
Level 2
10 replies posted 5 replies posted 5 questions asked
Level 2

Hi there,

Attached below is the pin configurator of our project where INPUT1, SHAFT_FRONT,SHAFT_BACK and Vin are the analog pins we have used in our pcb design. All those pins aren't on port 10 , is there any way we could still connect these analog pins to 4 different adc channels?

AyKo_4382201_0-1611298721700.png

 

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Vison_Zhang
Moderator
Moderator 500 replies posted 100 sign-ins 250 replies posted
Moderator

If  you use external AMUX component, that's ok. If you use the sar sequencer mux inside SARADC component, PORT10 is the must choice.

See below picture,  the sar sequencer mux inside SARADC component only controls the switches surround by red circle, the analog route connects these switches can only routed to PORT10 directly.  So if you have made the PCB board, you should use external AMUX component instead of sar sequencer mux.

 

Capture.PNG

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AyKo_4382201
Level 2
10 replies posted 5 replies posted 5 questions asked
Level 2

Okay, thanks for clearing our confusion.

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