Virtex 4 Configuration Pins

- A
- Anastasios D. Salis
  
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posted
17 years ago

Tue, Oct 3, 2006 10:16 AM

When designing using a Virtex 4 (VCCO_0 = 3.3V) and a XCF16PV(VCCO=3.3V and VCCJ=3.3V) at MASTER-SERIAL connection the special configuration pins "DONE", "PROG-B" and "INIT" need pull-up resistors. At which voltage rail should they be pulled up to? At 3.3V or 2.5V? When using a THEVENING termination for the CCLK, at which voltage should it be pulled up? In all those cases what value should the resistors have? I have used 100 Ohm for the thevening termination, 330 Ohm for INIT and DONE and 4.7K for PROG-B. In the ML401-2-3 reference schematic 2.5V is used for pull-up but in the Platform Flash Configuration guide (DS123) it says that I should pull the up to VCCO_0 that is 3.3 V in my case and in ML401_2_3 case also.

Please help me, I am cofused.

Thank you in advance, Tasos.

- J
- jerzy.gbur
  
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posted
17 years ago

Tue, Oct 3, 2006 12:34 PM

Anastasios D. Salis napisal(a):

VCCJ=3.3V) at MASTER-SERIAL connection the special configuration pins "DONE", "PROG-B" and "INIT" need pull-up resistors. At which voltage rail should they be pulled up to? At 3.3V or 2.5V? When using a THEVENING termination for the CCLK, at which voltage should it be pulled up? In all those cases what value should the resistors have? I have used 100 Ohm for the thevening termination, 330 Ohm for INIT and DONE and 4.7K for PROG-B. In the ML401-2-3 reference schematic 2.5V is used for pull-up but in the Platform Flash Configuration guide (DS123) it says that I should pull the up to VCCO_0 that is 3.3 V in my case and in ML401_2_3 case also.

I've got the similar issue, but Slave SelectMAP32 from microprocessor, Vcco = 3,3V. I haven't found special solution for this configuration in V4, so I use configuration from Spartan3 user guide (ds099.pdf

3.3V-Tolerant Configuration Interface).

I'm confused too :)

Regards

Jerzy Gbur

- V
- Vic Vadi
  
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posted
17 years ago

Fri, Oct 13, 2006 9:47 PM

As I answered on the other thread: If vcco_0 is 3.3V its essential that the pullups be to 3.3V also.

- Vic

snipped-for-privacy@gmail.com wrote:

VCCJ=3.3V) at MASTER-SERIAL connection the special configuration pins "DONE", "PROG-B" and "INIT" need pull-up resistors. At which voltage rail should they be pulled up to? At 3.3V or 2.5V? When using a THEVENING termination for the CCLK, at which voltage should it be pulled up? In all those cases what value should the resistors have? I have used 100 Ohm for the thevening termination, 330 Ohm for INIT and DONE and 4.7K for PROG-B. In the ML401-2-3 reference schematic 2.5V is used for pull-up but in the Platform Flash Configuration guide (DS123) it says that I should pull the up to VCCO_0 that is 3.3 V in my case and in ML401_2_3 case also.