Altera ALTDLL User Manual

Page 34

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3–16

Chapter 3: Parameter Settings

ALTDQ_DQS Parameter Editor

ALTDLL and ALTDQ_DQS Megafunctions User Guide

© February 2012

Altera Corporation

Table 3–9 on page 3–16

describes the options available on the OCT Path page. This

page allows you to configure the DQ and DQS OCT paths. For more information
about the DQ and DQS OCT paths, refer to

“DQ/DQS OCT Path” on page 4–14

.

Create
‘io_clock_divider
_slaveout’ output
port

USE_IO_CLOCK_

DIVIDER_SLAVEOUT

Enables the output of the divider’s D flip-flop (DFF). The
output signal can only be connected to the

masterin

input of another I/O clock divider block and it cannot
have more than one fan-out. Turn on this parameter
when you chain the I/O clock divider blocks from
multiple ALTDQ_DQS instances.

IO Clock Divider
Invert Phase

Always,
Never
, or
Based on
register
configuration

IO_CLOCK_DIVIDER_

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 register configuration, the

phaseinvertctrl

input determines whether or not

the inverter is used. The inverter can be used to increase
the number of available phases.

Table 3–8. Options on Half-Rate Page (Part 2 of 2)

Parameter Name

Legal Value

Clear Box

Parameter Name

Description

Table 3–9. Options on OCT Path Page

Parameter Name

Legal Value

Clear Box

Parameter Name

Description

Dynamic
Termination
Control Options

Enable Dynamic
Delay-chain1

USE_OCT_DELAY_

CHAIN1

Enables <IO>

_OCT_DELAY_CHAIN1

(D5) on both the

DQ and DQS dynamic OCT paths. The external memory
interfaces synchronize the timing of the turning on and
off of the parallel termination during reads and writes
from both the DQ and DQS pins, and to improve overall
timing margins.

D5 is a run-time adjustable delay chain.

For more information about configuring delay chains
dynamically, refer to

“Delay Chains” on page 4–15

.

Dynamic
Termination
Control Options

Enable Dynamic
Delay-chain2

USE_OCT_DELAY_

CHAIN2

Enables <IO>

_OCT_DELAY_CHAIN2

(D6) on both the

DQ and DQS dynamic OCT paths. The external memory
interfaces synchronize the timing of turning on and off of
the parallel termination during reads and writes from
both the DQ and DQS pins, and to improve overall timing
margins.

D6 is a run-time adjustable delay chain.

For more information about configuring delay chains
dynamically, refer to

“Delay Chains” on page 4–15

.

OCT register
mode

Not used, FF,
or DDIO

OCT_REG_MODE

Enables the full-rate dynamic OCT registers
(<IO>

_OCT_FF

or <IO>

_OCT_DDIO

registers) on

both the DQ and DQS dynamic OCT paths. Select FF if
you want flip-flop registers or DDIO if you want double
data rate I/O registers.

For more component information about this block, refer
to the “Dynamic On-Chip Termination Control” section in
the External Memory Interface chapter of the respective
device handbooks.

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