R
Pinout Descriptions
The XC3S250E FPGA in the FT256 package has 18 uncon-
nected balls, labeled with an “N.C.” type. These pins are
also indicated with the black diamond (ꢄ) symbol in
Figure 86.
User I/Os by Bank
Table 144, Table 145, and Table 146 indicate how the avail-
able user-I/O pins are distributed between the four I/O
banks on the FT256 package.
Table 144: User I/Os Per Bank on XC3S250E in the FT256 Package
All Possible I/O Pins by Type
Package
Edge
Maximum
I/O
(1)
(1)
I/O Bank
I/O
20
10
8
INPUT
DUAL
1
VREF
CLK
Top
0
1
2
3
44
42
10
7
5
4
8
(2)
Right
21
24
0
0
0
(2)
Bottom
Left
44
9
3
42
24
62
7
3
8
TOTAL
172
33
46
15
16
Notes:
1. Some VREF and CLK pins are on INPUT pins.
2. The eight global clock pins in this bank have optional functionality during configuration and are counted in the DUAL column.
Table 145: User I/Os Per Bank on XC3S500E in the FT256 Package
All Possible I/O Pins by Type
Package
Edge
Maximum
I/O
(1)
(1)
I/O Bank
I/O
22
15
11
28
76
INPUT
DUAL
1
VREF
CLK
Top
0
1
2
3
46
48
10
7
5
5
8
(2)
Right
21
24
0
0
0
(2)
Bottom
Left
48
9
4
48
7
5
8
TOTAL
190
33
46
19
16
Notes:
1. Some VREF and CLK pins are on INPUT pins.
2. The eight global clock pins in this bank have optional functionality during configuration and are counted in the DUAL column.
.
Table 146: User I/Os Per Bank on XC3S1200E in the FT256 Package
All Possible I/O Pins by Type
Package
Edge
Maximum
I/O
(1)
(1)
I/O Bank
I/O
24
14
13
27
78
INPUT
DUAL
1
VREF
CLK
Top
0
1
2
3
46
48
8
8
5
5
8
(2)
Right
21
24
0
0
0
(2)
Bottom
Left
48
7
4
48
8
5
8
TOTAL
190
31
46
19
16
Notes:
1. Some VREF and CLK pins are on INPUT pins.
2. The eight global clock pins in this bank have optional functionality during configuration and are counted in the DUAL column.
200
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DS312-4 (v3.8) August 26, 2009
Product Specification
XILINX [ XILINX, INC ]
