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200700560
Visitor
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Registered: ‎03-22-2010

XC9572XL : general inquiries!!

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Greetings,

 

I have three questions about using XC9572XL in my application:

 

1) If I need to use an external clock (cristal oscillator) for the CPLD. Do I need to connect it to all three XC9572XL global clock pins?

Is there any reason why this device has three GCK inputs?

 

2)  Is the XC9572XL compatible with the SPI communication protocol with a master microcontroller (where the CPLD is the slave)?

Do you recommend any other type of communication?

 

3)  I am worried about the power consumption of the CPLD. Will it need more than 0.5 A knowing that the oscillator to be used has a 16 MHz

frequency?

 

Thank you in advance for your help and cooperation. Your feedback is most appreciated.

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john.h
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Registered: ‎02-27-2010

The data sheet is your friend.  Please spend some quality time with your pdf reader, a nice big monitor, and a warm cup of coffee or tea.

 

 

Your oscillator only needs to be hooked up to one global clock.  There are multiple global clocks to support global clocking from multiple sources.

 

The SPI protocol isn't much more than a shift register.  As long as the voltages for the two devices match, everything flows fine.

 

The power consumption won't be extreme.  With no loads at 1 MHz, the data sheet suggests 20mA is the expeced current draw.  If you load every output with 20 ohm resistors, your results may be different.  The power graph on the first page of the data sheet I glanced at suggests that at 16MHz in high performance mode you'll draw about 40mA.

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john.h
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Registered: ‎02-27-2010

The data sheet is your friend.  Please spend some quality time with your pdf reader, a nice big monitor, and a warm cup of coffee or tea.

 

 

Your oscillator only needs to be hooked up to one global clock.  There are multiple global clocks to support global clocking from multiple sources.

 

The SPI protocol isn't much more than a shift register.  As long as the voltages for the two devices match, everything flows fine.

 

The power consumption won't be extreme.  With no loads at 1 MHz, the data sheet suggests 20mA is the expeced current draw.  If you load every output with 20 ohm resistors, your results may be different.  The power graph on the first page of the data sheet I glanced at suggests that at 16MHz in high performance mode you'll draw about 40mA.

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200700560
Visitor
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Registered: ‎03-22-2010

Thx for your help John and for the advice regarding the data sheet.:manhappy:  

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200700560
Visitor
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Registered: ‎03-22-2010

One more questions regarding the SPI communication.

What are the recommend pins that I could use for data transfer to the microcontroller?

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john.h
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Registered: ‎02-27-2010
The only recommendation is to use a single GCLK pin for your SCLK.  The MISO and MOSI as well as the SS can go pretty much on any I/O.
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200700560
Visitor
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Registered: ‎03-22-2010

Thank you one more Mr. John h.

:smileyhappy:

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200700560
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Registered: ‎03-22-2010
*one more time
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