Altera ALTDLL - Manual (Page 87)

4–51 Chapter 4: Functional Description
Design Example: Implementing Half-Rate DDR2 Interface in Stratix III
ALTDLL and ALTDQ_DQS Megafunctions User Guide © February 2012 Altera Corporation
Instantiate the ALTDQ_DQS Megafunction
To instantiate the ALTDQ_DQS megafunction, perform the following steps:
1. On the Tools menu, click MegaWizard Plug-In Manager. Page 1 of the
MegaWizard Plug-In Manager appears.
2. Select Create a new custom megafunction variation.
3. Click Next. Page 2a of the MegaWizard Plug-In Manager appears. Select
ALTDQ_DQS , and Verilog HDL, and type the file name as dq_dqs_inst.v.
4. On the Parameter Settings page of the ALTDQ_DQS parameter editor, specify the
parameters as shown in Table 4–26 .
5. In the Advanced Options tab of the ALTDQ_DQS parameter editor, on the DQS
IN page, specify the parameters as shown in Table 4–27 . These parameters
configure the DQS input path of the ALTDQ_DQS instance.
Table 4–26. Parameter Settings
Parameter Value
RLDRAM II Mode NONE
Data mask pin group NONE
Q valid signal group NONE
Number of bidirectional DQ 8
Number of input DQ 0
Number of output DQ 1
Number of stages in dqs_delay_chain 2
DQS Input Frequency 333 MHz
Use half-rate components Turned on
Use Dynamic OCT Turned off
Add memory interface specific fitter grouping assignments Turned off
Table 4–27. Advanced Options (DQS IN) (Part 1 of 2)
Parameter Sub-options Value
Enable DQS Input Path — Turned on
Enable Dynamic Delay Chain — Not selected
Enable dqs_delay_chain — Selected
Advanced delay chain options Select dynamically using
configuration registers Turned off
DQS delay chain ‘delayctrlin’ port
source DLL
DQS Delay Buffer Mode HIGH
DQS Phase Shift 9000..
Enable DQS offset Control Turned off
Enable DQS delay chain latches Turned off
Enable DQS busout delay chain — Turned on
Enable DQS enable block — Turned on
Enable DQS enable control block — Turned on