R
Spartan and Spartan-XL Families Field Programmable Gate Arrays
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. Because only Spartan-XL, XC4000XLA/XV, and
XC5200 devices support Express mode, only these devices
can be used to form an Express mode daisy chain.
V
CC
8
To Additional
M0
M1
M0
M1
Optional
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
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DS060 (v1.6) September 19, 2001
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Product Specification