Altera ALTDLL - Manual (Page 25)

Chapter 3: Parameter Settings 3–7
ALTDQ_DQS Parameter Editor
© February 2012 Altera Corporation ALTDLL and ALTDQ_DQS Megafunctions User Guide
The Advanced Options page allows you to configure the parameters in the following
pages:
■ DQS IN
■ DQS OUT/OE
■ DQ IN
■ DQ OUT/OE
■ Half-rate
■ OCT Path
■ DQSn I/O
Number of input
DQ 0–48 NUMBER_OF_
INPUT_DQ
Specifies the number of input DQ ports used in the
ALTDQ_DQS instance.
Number of output
DQ 0–48 NUMBER_OF_
OUTPUT_DQ
Specifies the number of output DQ ports used in the
ALTDQ_DQS instance.
Number of stages
in
dqs_delay_chain 1, 2, 3, and 4 DQS_DELAY_CHAIN_
PHASE_SETTING
Specifies the stages of DQS_DELAY_CHAIN . The
number of stages depends on the intended phase shift
that you want to clock for <IO>
_DDIO_IN block in the
DQ input path. The bigger the value you specify, the longer
the delay.
The coarse phase shift depends on this option. For
example, in Stratix IV devices, if you set the frequency
mode to 1, you will get a phase shift of 20°, 60°, 90°, or
120°. If you set Number of stages in dqs_delay_chain
value to 2, you will get 60° phase shift and if you set the
Number of stages in dqs_delay_chain value to 1, you will
get 30° phase shift.
DQS input
frequency — DQS_INPUT_
FREQUENCY
Specifies the input frequency of the DQS strobe in MHz.
The input frequency must match the DLL (ALTDLL) input
frequency.
Use half rate
components — USE_HALF_RATE Instantiates the half-rate blocks in the ALTDQ_DQS
instance. This parameter is used only when the external
memory interface requires half-rate mode.
Not supported in Arria II GX devices.
Use dynamic OCT
path — USE_DYNAMIC_OCT Instantiates the dynamic OCT blocks in the ALTDQ_DQS
instance. This parameter enables access to dynamic OCT
paths on both DQ and DQS paths. The dynamic OCT
features enable parallel termination (R
t
) during reads from
the external memory and disable R
t
during writes to the
external memory.
Not supported in Arria II GX devices.
Add memory
interface specific
fitter grouping
assignments — ADD_MEM_FITTER_
GROUP_ASSIGNMENTS
Enables the Quartus II Fitter to automatically assign the
memory interface I/O ports to the memory interface I/O
pins on the FPGA.
Table 3–3. Options on Parameter Settings Page (Part 2 of 2)
Parameter Name Legal Value
Clear Box
Parameter Name Description