AR #15720 - 5.1i CPLD Hprep6 CoolRunner-II - VREF I/O Standards (HSTL-1, SSTL2-1, SSTL 3-1) are not working on the device
5.1i CPLD Hprep6 CoolRunner-II - VREF I/O Standards (HSTL-1, SSTL2-1, SSTL 3-1) are not working on the device
| AR# | 15720 |
| Part | hprep6 |
| Last Modified | 2002-12-09 00:00:00.0 |
| Status | Active |
| Keywords | 5.1i, CPLD, Hprep6, CoolRunner-II, VREF, HSTL-1, SSTL2-1, SSTL 3-1, termination |
Description
Keywords: 5.1i, CPLD, Hprep6, CoolRunner-II, VREF, HSTL-1, SSTL2-1, SSTL 3-1, termination
Urgency: Standard
General Description:
When I implement an I/O Standard that requires a VREF (HSTL-1, SSTL2-1, SSTL 3-1), the inputs do not function correctly on the device.
Solution
This problem is due to bug that occurs when the VREF pins are being terminated internally (either with bus-hold or with a weak pull-up).This problem is fixed in the latest 5.1i Service Pack, available at:
http://support.xilinx.com/support/techsup/sw_updates
The first service pack containing the fix is 5.1i Service Pack 3.