
Altera Corporation
2–75
May 2007
Stratix II Device Handbook, Volume 1
Stratix II Architecture
Figure 2–50. Control Signal Selection per IOE
(1)
Control signals ce_in, ce_out, aclr/apreset, sclr/spreset, and oe can be global signals even though their
control selection multiplexers are not directly fed by the ioe_clk[7..0] signals. The ioe_clk signals can drive
the I/O local interconnect, which then drives the control selection multiplexers.
In normal bidirectional operation, the input register can be used for input
data requiring fast setup times. The input register can have its own clock
input and clock enable separate from the OE and output registers. The
output register can be used for data requiring fast clock-to-output
performance. The OE register can be used for fast clock-to-output enable
timing. The OE and output register share the same clock source and the
same clock enable source from local interconnect in the associated LAB,
dedicated I/O clocks, and the column and row interconnects.
clk_out
ce_in
clk_in
ce_out
aclr/apreset
sclr/spreset
Dedicated I/O
Clock [7..0]
Local
Interconnect
Local
Interconnect
Local
Interconnect
Local
Interconnect
Local
Interconnect
oe
io_oe
io_aclr
Local
Interconnect
io_sclr
io_ce_out
io_ce_in
io_clk