Altera ALTDLL - Manual (Page 28)

3–10 Chapter 3: Parameter Settings
ALTDQ_DQS Parameter Editor
ALTDLL and ALTDQ_DQS Megafunctions User Guide © February 2012 Altera Corporation
Table 3–5 describes options available on the DQS OUT/OE page. This page allows
you to configure the DQS output and output enable (OE) paths. For more information
about the DQS output and OE paths, refer to
“DQS Output/OE Path” on page 4–12 .
Advanced Delay
Chain Options
Enable DQS
delay chain
latches
— DQS_CTRL_LATCHES_
ENABLE
Enables the delayctrlin[5..0] and
offsetctrlin[5..0] inputs to be registered by
the dqsupdateen signal. The DLL continues changing
its delay settings value due to the feedback system.
These DLL values are propagated through the
delayctrlout and offsetctrlout signals of
the DLL and DLL offset control blocks to
DQS_DELAY_CHAIN block to calibrate the necessary
delay settings. These values are updated based on the
dll_dqsupdate port from the DLL, which is
connected to the dqsupdateen port. To use this
option, you must turn on the Create a ‘use
dll_dqsupdate’ port option on the DLL Offset
Controls/Optional Ports page in the ALTDLL parameter
editor.
Advanced Enable
Control Options
DQS Enable
Control Phase
Setting
Set statically
to
or
Set
dynamically
using
configuration
registers
DQS_ENABLE_CTRL_
PHASE_SETTING
If you turn on the Set statically to option, you can select
the phase setting for the delay chains from 0 up to 4 to
fine-tune the DQS enable signal.
If you turn on the Select dynamically using
configuration registers option, the phase setting is
determined by the
phasectrlin input for the delay
chains.
Advanced Enable
Control Options
DQS Enable
Control Invert
Phase
Always,
Never, or
Based on
configuration
registers DQS_ENABLE_CTRL_
INVERT_PHASE
If you turn on Always, the phase output is inverted.
If you turn on Never, the phase output is not inverted.
If you turn on Based on configuration registers, the
phaseinvertctrl input determines whether or not
the inverter is used. The inverter can be used to increase
the number of available phases. This is an optional field
and defaults to Never.
Enable DQS
enable block
delay chain — USE_DQSENABLE_
DELAY_CHAIN
Enables DQS_ENABLE_DELAY_CHAIN . This delay
chain fine-tunes the outputs of DQS_ENABLE_CTRL
block so that the DQS enable signal timing matches the
DQS strobe. This delay chain is a run-time adjustable
delay chain.
Table 3–4. Options on DQS IN Page (Part 3 of 3)
Parameter Name Legal Value
Clear Box
Parameter Name Description
Table 3–5. Options on DQS OUT/OE Page (Part 1 of 2)
Parameter Name Legal Value
Clear Box
Parameter Name Description
Enable DQS
output path — USE_DQS_OUTPUT_
PATH
Instantiates the DQS output path.
Enable DQS
output path — USE_DQS_OUTPUT_
PATH
Instantiates the DQS output path.