R
Spartan and Spartan-XL FPGA Families Data Sheet
to the DONE pin. User I/Os for each device become active
after the DONE pin for that device goes High. (The exact
timing is determined by development system options.)
Since the DONE pin is open-drain and does not drive a High
value, tying the DONE pins of all devices together prevents
all devices in the chain from going High until the last device
in the chain has completed its configuration cycle. If the
DONE pin of a device is left unconnected, the device
becomes active as soon as that device has been config-
ured. Only devices supporting Express mode can be used
to form an Express mode daisy chain.
V
CC
8
To Additional
Optional
M0
M1
M0
M1
Daisy-Chained
Devices
CS1
CS1
DOUT
DOUT
8
8
D0-D7
D0-D7
DATA BUS
Optional
Daisy-Chained
Spartan-XL
VCC
3.3K
Spartan-XL
PROGRAM
INIT
PROGRAM
PROGRAM
INIT
INIT
CCLK
DONE
DONE
CCLK
To Additional
Optional
Daisy-Chained
Devices
CCLK
DS060_27_080400
Figure 27: Express Mode Circuit Diagram
30
www.xilinx.com
DS060 (v1.8) June 26, 2008
Product Specification
XILINX [ XILINX, INC ]
