Altera ALTDLL - Manual (Page 8)

Chapter 2: Getting Started 2–2
Design Flow
© February 2012 Altera Corporation ALTDLL and ALTDQ_DQS Megafunctions User Guide
4. Instantiate the ALTDQ_DQS megafunction to implement the read and write PHY
required for the interface.
5. Integrate the custom PHY with user logic, and a custom or third party memory
controller if needed.
6. Instantiate the ALTIOBUF megafunction to use the I/O buffers for pin
connections. This megafunction enables dynamic OCT capabilities for the
respective interface pins.
f
For more information about the pin connections, refer to “ALTIOBUF
Megafunction and Delay Chains Integration” on page 4–18 . For more
information about the ALTIOBUF megafunction, refer to I/O Buffer
(ALTIOBUF) Megafunction User Guide .
7. Connect all the instances of ALTPLL, ALTDLL, ALTDQ_DQS, ALTIOBUF, and
other custom memory controllers in the Quartus II software.
The following sections discuss other megafunctions or customized controller logic
that are used in some cases.
ALTOCT Megafunction
If you use the OCT capabilities in the targeted devices, you eliminate the need for
external series or parallel termination resistors, and you simplify the design of a PCB.
If the I/O in your design uses calibrated series, parallel, or dynamic termination, your
design requires a calibration block. This block requires a pair of
R
UP
and R
DN
pins
located in a bank that shares the same V
CCIO
voltage as your memory interface. This
calibration block is not required to be in the same bank or side of the device as the I/O
elements it is serving. To use these capabilities in the FPGA, you must turn on the Use
dynamic OCT path
option when parameterizing the ALTDQ_DQS megafunction,
and instantiate the ALTOCT megafunction.
f For more information about the OCT capabilities in the DQ/DQS path, refer to
“DQ/DQS OCT Path” on page 4–14 .
Customized Controller Logic
In some cases, you require a customized controller logic to control the PHY created
with the ALTDLL and ALTDQ_DQS instances. You must create a controller logic for
the following instances:
■ Controller logic for data, data_valid, and strobe pins for the custom external
memory interface.
■ If you use calibrated termination, controller logic for all pins in the ALTOCT
instances associated with the custom external memory interface.
f
For more information about calibrated termination, refer to Dynamic
Calibrated On-Chip Termination (ALTOCT) Megafunction User Guide .