XC2VP20-6FF1152C Xilinx, Inc., XC2VP20-6FF1152C Datasheet - Page 38

• Manufacturer Part Number: XC2VP20-6FF1152C
• Description: Pro Platform FPGA
• 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.
CLB/Slice Configurations
Table 13
the CLBs are identical and each CLB or slice can be imple-
Table 13: Logic Resources in One CLB
38
Slices
4
Figure 33: Virtex-II Pro 3-State Buffers
summarizes the logic resources in one CLB. All of
Switch
Matrix
LUTs
8
Figure 34: 3-State Buffer Connection to Horizontal Lines
Switch
CLB-II
matrix
Flip-Flops
Slice
Slice
TBUF
TBUF
S1
S0
8
DS031_37_060700
Programmable
connection
Slice
Slice
S3
S2
MULT_ANDs
8
Figure
www.xilinx.com
Switch
CLB-II
1-800-255-7778
matrix
33.
Carry-Chains
Arithmetic &
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.
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 12
each Virtex-II Pro device. The number of 3-state buffers is
twice the number of CLB elements.
Table 12: Virtex-II Pro 3-State Buffers
mented in one of the configurations listed.
the available resources in all CLBs.
2
XC2VP2
XC2VP4
XC2VP7
XC2VP20
XC2VP50
Device
shows the number of 3-state buffers available in
Figure
Chains
DS031_09_032700
3 - state lines
SOP
2
34. The switch matrices corresponding to
3-State Buffers
Distributed
SelectRAM
per Row
128 bits
140
44
44
68
92
DS083-2 (v1.0) January 31, 2002
Advance Product Specification
Registers
of 3-State Buffers
128 bits
Shift
Total Number
Table 14
12,320
1,760
2,720
5,152
704
TBUF
shows
2
R