XC2VP70 Xilinx, Inc., XC2VP70 Datasheet - Page 41

• Manufacturer Part Number: XC2VP70
• Description: Virtex-ii Pro Field Programmable Gate Array
• Manufacturer: Xilinx, Inc.

Functional Description: FPGA
3-State Buffers
Introduction
Each Virtex-II Pro CLB contains two 3-state drivers
(TBUFs) that can drive on-chip buses. Each 3-state buffer
has its own 3-state control pin and its own input pin.
Each of the four slices have access to the two 3-state buff-
ers through the switch matrix, as shown in
TBUFs in neighboring CLBs can access slice outputs by
direct connects. The outputs of the 3-state buffers drive hor-
izontal routing resources used to implement 3-state buses.
The 3-state buffer logic is implemented using AND-OR logic
rather than 3-state drivers, so that timing is more predict-
able and less load dependant especially with larger devices.
CLB/Slice Configurations
Table 14
the CLBs are identical and each CLB or slice can be imple-
Table 14: Logic Resources in One CLB
32
Slices
4
Figure 36: Virtex-II Pro 3-State Buffers
summarizes the logic resources in one CLB. All of
Switch
Matrix
LUTs
8
Figure 37: 3-State Buffer Connection to Horizontal Lines
Switch
matrix
CLB-II
Flip-Flops
Slice
Slice
TBUF
TBUF
S1
S0
8
DS031_37_060700
Programmable
connection
Slice
Slice
S3
S2
MULT_ANDs
8
Figure
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Switch
1-800-255-7778
CLB-II
matrix
36.
Carry-Chains
Arithmetic &
Locations / Organization
Four horizontal routing resources per CLB are provided for
on-chip 3-state buses. Each 3-state buffer has access alter-
nately to two horizontal lines, which can be partitioned as
shown in
SelectRAM+ memory and multiplier or I/O blocks are
skipped.
Number of 3-State Buffers
Table 13
each Virtex-II Pro device. The number of 3-state buffers is
twice the number of CLB elements.
Table 13: Virtex-II Pro 3-State Buffers
mented in one of the configurations listed.
the available resources in all CLBs.
2
XC2VP2
XC2VP4
XC2VP7
XC2VP20
XC2VP30
XC2VP40
XC2VP50
XC2VP70
XC2VP100
XC2VP125
Device
shows the number of 3-state buffers available in
Figure
Chains
DS031_09_032700
3 - state lines
SOP
2
37. The switch matrices corresponding to
3-State Buffers
SelectRAM+
Distributed
per Row
128 bits
116
140
164
188
212
44
44
68
92
92
DS083-2 (v2.9) October 14, 2003
Advance Product Specification
Registers
of 3-State Buffers
128 bits
Shift
Total Number
Table 15
11,808
16,544
22,048
27,808
1,760
2,720
5,152
6,848
9,696
704
TBUF
shows
2
R