atf280e ATMEL Corporation, atf280e Datasheet - Page 20

• Manufacturer Part Number: atf280e
• Description: Rad Hard Reprogrammable Fpga
• Manufacturer: ATMEL Corporation

4.3.1
20
Cell Output Enable
RAM Output Enable
RAM Write Enable
RAM Address
RAM Data In
RAM Data Out
Clocking
Set/Reset
Function
ATF280E
Dual Function Bus Resource
Although not shown, a local bus can bypass a repeater via a programmable pass gate allowing
long on-chip tri-state buses to be created. Local/Local turns are implemented through pass
gates in the cell-bus interface (see following page).
Express/Express turns are implemented through separate pass gates distributed throughout the
array.
Some of the bus resource on the ATF280E are used as a dual-function resource. The table
hereafter shows which buses are used in a dual-function mode and which bus plane is used.
Table 4-1.
The ATF280E software tools are designed to accommodate dual-function buses in an efficient
manner
Express
Express
Express
Express
Express
Local
Local
Local
Type
Dual-function Buses
Plane(s)
1 - 5
5
2
1
1
2
4
5
Horizontal and
Horizontal
Horizontal
Direction
Vertical
Vertical
Vertical
Vertical
Vertical
Vertical
Bus full length at array edge
Bus in first column to left of RAM block
Bus full length at array edge
Bus in first column to left of RAM block
Buses full length at array edge
Buses in second column to left of RAM block
Bus half length at array edge
Bus half length at array edge
Comments
7750A–AERO–07/07