Xilinx MIcroblaze Development Spartan-3E 1600E - Manual (Page 133)

MicroBlaze Development Kit Spartan-3E 1600 Edition User Guide 131
UG257 (v1.1) December 5, 2007 www.xilinx.com
R
Chapter 17
DS2432 1-Wire SHA-1 EEPROM
The MicroBlaze Development Kit board includes a Maxim DS2432 serial EEPROM with an
integrated SHA-1 engine. As shown in Figure 17-1 , the DS2432 EEPROM uses the Maxim
1-Wire interface, which uses a single wire for power and serial communication.
The DS2432 EEPROM offers one of many possible means to copy and protect the FPGA
configuration bitstream, thereby making cloning difficult. Xilinx application note
XAPP780, listed under “Related Resources” provides one possible implementation
method.
UCF Location Constraints
Figure 17-2 provides the UCF constraints for the FPGA connections to the DS2432 SHA-1
EEPROM, including the I/O pin assignment and the I/O standard used.
Related Resources
x Maxim DS2432 1-Wire EEPROM with SHA-1 Engine
http://www.maxim-ic.com/quick_view2.cfm/qv_pk/2914
x XAPP780: FPGA IFF Copy Protection Using Dallas Semiconductor/Maxim DS2432 Secure
EEPROMs
http://www.xilinx.com/bvdocs/appnotes/xapp780.pdf
Figure 17-1: SHA-1 EEPROM
Maxim DS2432
SHA-1 EEPROM
(U4)
Spartan-3E FPGA
3.3v
DS_WIRE
GND
UG257_16_01_060806
Figure 17-2: UCF Location Constraints for DS2432 SHA-1 EEPROM
NET "DS_WIRE" LOC = "U4" | IOSTANDARD = LVCMOS33 | SLEW = SLOW | DRIVE = 8 ;
UG257_17_02_061606