EP2S15 ALTERA [Altera Corporation], EP2S15 Datasheet - Page 78

• Manufacturer Part Number: EP2S15
• Description: Stratix II Device Family
• Manufacturer: ALTERA [Altera Corporation]

I/O Structure
2–70
Stratix II Device Handbook, Volume 1
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The IOE in Stratix II devices contains a bidirectional I/O buffer, six
registers, and a latch for a complete embedded bidirectional single data
rate or DDR transfer.
IOE contains two input registers (plus a latch), two output registers, and
two output enable registers. The design can use both input registers and
the latch to capture DDR input and both output registers to drive DDR
outputs. Additionally, the design can use the output enable (OE) register
for fast clock-to-output enable timing. The negative edge-clocked OE
register is used for DDR SDRAM interfacing. The Quartus II software
automatically duplicates a single OE register that controls multiple
output or bidirectional pins.
Output drive strength control
Tri-state buffers
Bus-hold circuitry
Programmable pull-up resistors
Programmable input and output delays
Open-drain outputs
DQ and DQS I/O pins
Double data rate (DDR) registers
Figure 2–46
shows the Stratix II IOE structure. The
Altera Corporation
May 2007