Scan_Enable signal

clarkb · ‎2003-11-27

Posted on November 27, 2003 at 10:08

Scan_Enable signal

clarkb · ‎2003-05-01

Posted on May 01, 2003 at 12:52

I wonder what affect having the Scan_Enable lead tied to ground will have on the Boundary Scan interface on the STPC Elite device.

moedeker2 · ‎2003-05-14

Posted on May 15, 2003 at 07:24

Hi, what curious affect you mean?

I have a chain with an XILINX-XC9572XL-CPLD. I could not program or access the CPLD when STPC Elite is in the chain. If I cut STPC Elite out of the chain the access to CPLD is without any problems.

Could the SCAN_ENABLE the problem? I have tied it to GND.

Benno

jima · ‎2003-11-20

Posted on November 20, 2003 at 17:02

Did you ever get the STPC in the scan chain?

moedeker2 · ‎2003-11-26

Posted on November 27, 2003 at 04:47

I did'nt!

ST seems not to be able to explain the SCAN_ENABLE signal functionality.

stephen239955_st · ‎2003-11-27

Posted on November 27, 2003 at 10:08

The Scan_Enable pin is a reserved pin on the STPC. It is used for manufacturing testing purposes only and should not be set any other value than that given the schematics.

Also, the JTAG in the STPC Elite (and all the others for that matter) is only used for Boundary scan purposes only. It cannot be used for any thing else. If you want to programme external flashes or EPLDs for example, you must implement 2 scan chains.