R
Functional Description
The XC3S1600E requires an 8 Mbit PROM. Two solutions
are possible: either a single 8 Mbit XCF08P parallel/serial
PROM or two 4 Mbit XCF04S serial PROMs cascaded. The
Voltage Compatibility
The PROM’s V
supply must be either 3.3V for the
CCINT
serial XCFxxS Platform Flash PROMs or 1.8V for the
serial/parallel XCFxxP PROMs.
two XCF04S PROMs use a 3.3V V
supply while the
CCINT
XCF08P requires a 1.8V V
supply. If the board does
CCINT
V
The FPGA’s VCCO_2 supply input and the Platform
not already have a 1.8V supply available, the two cascaded
XCF04S PROM solution is recommended.
Flash PROM’s V
supply input must be the same volt-
CCO
age, ideally +2.5V. Both devices also support 1.8V and 3.3V
interfaces but the FPGA’s PROG_B and DONE pins require
special attention as they are powered by the FPGA’s
CCLK Frequency
In Master Serial mode, the FPGA’s internal oscillator gener-
ates the configuration clock frequency. The FPGA provides
this clock on its CCLK output pin, driving the PROM’s CLK
input pin. The FPGA starts configuration at its lowest fre-
quency and increases its frequency for the remainder of the
configuration process if so specified in the configuration bit-
stream. The maximum frequency is specified using the
ConfigRate bitstream generator option. Table 52 shows the
maximum ConfigRate settings, approximately equal to
MHz, for various Platform Flash devices and I/O voltages.
For the serial XCFxxS PROMs, the maximum frequency
also depends on the interface voltage.
V
supply, nominally 2.5V. See application note
CCAUX
XAPP453: The 3.3V Configuration of Spartan-3 FPGAs for
additional information.
Supported Platform Flash PROMs
Table 51 shows the smallest available Platform Flash
PROM to program one Spartan-3E FPGA. A multiple-FPGA
daisy-chain application requires a Platform Flash PROM
large enough to contain the sum of the various FPGA file
sizes.
Table 51: Number of Bits to Program a Spartan-3E
FPGA and Smallest Platform Flash PROM
Table 52: Maximum ConfigRate Settings for Platform
Flash
Number of
Spartan-3E
FPGA
Configuration
Bits
SmallestAvailable
Platform Flash
Maximum
ConfigRate
Setting
Platform Flash
Part Number
I/O Voltage
(VCCO_2, V
)
CCO
XC3S100E
XC3S250E
XC3S500E
XC3S1200E
581,344
1,353,728
2,270,208
3,841,184
5,969,696
XCF01S
XCF02S
XCF04S
XCF04S
XCF01S
XCF02S
XCF04S
3.3V or 2.5V
1.8V
25
12
XCF08P
XCF16P
XCF32P
3.3V, 2.5V, or 1.8V
25
XCF08P
or 2 x XCF04S
XC3S1600E
74
www.xilinx.com
DS312-2 (v3.8) August 26, 2009
Product Specification
XILINX [ XILINX, INC ]
