EP1C4 ALTERA [Altera Corporation], EP1C4 Datasheet - Page 51

• Manufacturer Part Number: EP1C4
• Description: Cyclone FPGA Family Data Sheet
• Manufacturer: ALTERA [Altera Corporation]

Figure 2–32. Cyclone IOE in Bidirectional I/O Configuration
Altera Corporation
January 2007
Column or Row
Interconect
ioe_clk[5..0]
comb_datain
data_in
Chip-Wide Reset
OE
clkout
aclr/prn
ce_in
ce_out
clkin
sclr/preset
The Cyclone device IOE includes programmable delays to ensure zero
hold times, minimize setup times, or increase clock to output times.
A path in which a pin directly drives a register may require a
programmable delay to ensure zero hold time, whereas a path in which a
pin drives a register through combinatorial logic may not require the
delay. Programmable delays decrease input-pin-to-logic-array and IOE
input register delays. The Quartus II Compiler can program these delays
Output Register
Input Register
OE Register
D
D
D
CLRN
CLRN
CLRN
PRN
ENA
PRN
ENA
PRN
ENA
Q
Q
Q
Pin Delay
Drive Strength Control
Output
Open-Drain Output
Slew Control
Input Register Delay
Logic Array Delay
Logic Array Delay
or Input Pin to
Input Pin to
Input Pin to
V
CCIO
V
CCIO
Optional
PCI Clamp
I/O Structure
Preliminary
Bus Hold
Programmable
Pull-Up
Resistor
2–45