kdb339: FreeForm/104 Spartan 3E Steppings

Title: FreeForm/104 Spartan 3E Steppings
Keywords: PC/104, Spartan-3E, FPGA, FreeForm/104, Steppings, FBG
Date: 2013/03/01
KDB: KDB-339
Revision: 0.00
Author: MF
Distribution: External

Introduction

In some cases Connect Tech may have produced FreeForm/104 products using Spartan-3E silicon Stepping Number 0.
This might impact several timing paramters including DCM performance

Differences between steppings

From Xilinx DS312  Table 71:
Stepping 0

  • Production from 2005 to 2007
  • Speed grade and operating conditions =  4C only
  • DCM maximum input frequency = 90 MHz
  • DCM DFS output frequency range = 5 – 90 MHz and  220 – 307 MHz
  • JTAG ID = 0x01C 22 093 or 0x11C 22 093

Stepping 1:

  • Production from 2006 to now
  • Speed grade and operating conditions = -4C, -4I, -5C
  • DCM maximum input frequency = 240 MHz
  • DCM DFS output frequency range = 5 – 311 MHz
  • JTAG ID = 0x21C 22 093

Products Affected

Only commercial temperature grade boards (FBG001, FBG002, FBG003, FBG004, FBG008) are affected.

How to determine if a board uses a device with Stepping 0

– Use Xilinx Impact and read back the JTAG ID, see Xilinx DS312  Table 67
– Viewing the BGA top side marking, 2nd last line, the final digit will indicate the stepping, see Xilinx DS312  Table Figure 2

Designing with Stepping 0

It is not possible for the Xilinx ISE tools ( after ISE 8.x) to target the stepping code; so the designer will have to be aware of the limitations.

End of KDB-339

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