Data Sheet
June 1999
ORCA Series 3C and 3T FPGAs
Programmable Logic Cells (continued)
General Routing Structure
Routing resources in Series 3 FPGAs generally consist of routing segments in groups of ten, with varying lengths
and connectivity to logic and other routing resources. The varying lengths of routing segments provides a hierarchy
of routing capability from chip-length routes to routes within a PLC. The hierarchical nature of the routing provides
the ORCA Foundry development tools with the necessary resources to route a design completely and to optimize
the routing for system speed while reducing the overall power required by the device.
Within each group of ten routing segments there is an equivalency of connectivity between pairs of segments.
These pairs are segments: [0, 4] and [1, 5] and [2, 6] and [3, 7] and [8, 9]. The equivalency in connectivity ensures
that signals on either segment in a pair have the same capability to get to a given destination. This, in turn, allows
for signal distribution from a source to varying destinations without using special routing. It also provides for routing
flexibility by ensuring that one segment position will not become so congested as to preclude routing a bus or group
of signals and allows easy connectivity from either of the twin quads in a source PFU to either of the twin quads in
any destination PFU.
Having ten segments in a group is significant in that it provides for routing a byte of data and two control signals or
parity. Due to the equivalent pairs of segments, this can also be viewed as routing two nibbles each with a control
signal. Figure 19 is an overview of the routing for a single PLC.
hxH[9:0]
hx1U[9:0]
hCK
FC
FC
SLL[9:0]
SLL[9:0]
FINS
PFU
5
2
SLR[9:0]
SLIC
OUTPUT
SWITCHING
SUR[9:0]
LCK
hx1B[9:0]
hx5[9:0]
hxL[9:0]
BR[9:0]
2
5
BR[9:0]
SUL[9:0]
SUL[9:0]
FC
BL[9:0]
KEY: CONFIGURABLE SIGNAL LINE BREAKS
LINE-BY-LINE
2
2 OF 5
5
5-5766(F)
Figure 19. Single PLC View of Inter-PLC Route Segments
28
Lucent Technologies Inc.
AGERE [ AGERE SYSTEMS ]
