Stratix II Architecture
Figure 2–33. Dual-Regional Clocks
Clock Pins or PLL Clock Outputs
Can Drive Dual-Regional Network
Clock Pins or PLL Clock
Outputs Can Drive
Dual-Regional Network
CLK[15..12]
CLK[15..12]
CLK[3..0]
CLK[11..8]
CLK[3..0]
CLK[11..8]
PLLs
PLLs
CLK[7..4]
CLK[7..4]
Combined Resources
Within each quadrant, there are 24 distinct dedicated clocking resources
consisting of 16 global clock lines and eight regional clock lines.
Multiplexers are used with these clocks to form busses to drive LAB row
clocks, column IOE clocks, or row IOE clocks. Another multiplexer is
used at the LAB level to select three of the six row clocks to feed the ALM
registers in the LAB (see Figure 2–34).
Figure 2–34. Hierarchical Clock Networks Per Quadrant
Clocks Available
to a Quadrant
or Half-Quadrant
Column I/O Cell
IO_CLK[7..0]
Global Clock Network [15..0]
Regional Clock Network [7..0]
Clock [23..0]
Lab Row Clock [5..0]
Row I/O Cell
IO_CLK[7..0]
Altera Corporation
May 2007
2–51
Stratix II Device Handbook, Volume 1
ALTERA [ ALTERA CORPORATION ]
