Altera QDRII SRAM Controller MegaCore Function - Manual (Page 42)

3–10 MegaCore Version 9.1 Altera Corporation
QDRII SRAM Controller MegaCore Function User Guide November 2009
OpenCore Plus Time-Out Behavior
Figure 3–6. Timing Diagram of the IOE
OpenCore Plus
Time-Out
Behavior OpenCore Plus hardware evaluation can support the following two
modes of operation:
■ Untethered—the design runs for a limited time
■ Tethered—requires a connection between your board and the host
computer. If tethered mode is supported by all megafunctions in a
design, the device can operate for a longer time or indefinitely
All megafunctions in a device time out simultaneously when the most
restrictive evaluation time is reached. If there is more than refer to one
megafunction in a design, a specific megafunction’s time-out behavior
may be masked by the time-out behavior of the other megafunctions.
1 For MegaCore functions, the untethered time out is 1 hour; the
tethered time out value is indefinite.
Your design stops working after the hardware evaluation time expires,
the reads and writes go low, and the wait output goes high.
f
For more information on OpenCore Plus hardware evaluation, refer to
“OpenCore Plus Evaluation” on page 1–3 and AN 320: OpenCore Plus
Evaluation of Megafunctions .
Interfaces &
Signals This section describes the following topics:
■ “Interface Description” on page 3–10
■ “Signals” on page 3–22
Interface Description
This section describes the following Avalon interface requests:
cqn
cq
I/O A[7:0]
Expected B[7:0]
Real B[7:0]
Usable
part of B[7:0]
Delayed cq
00 01 02 03 03
00 01 02 03 02
00 01 02 03 03
00 01 02 03 03