Altera Double Data Rate I/O User Manual
Page 5
Parameter
Description
Width: (bits)
Specify the width of the data buses.
Asynchronous clear and asynchronous set ports
Select Use ‘aclr’ port for asynchronous clear (aclr).
Select Use ‘aset’ port for asynchronous preset (aset)
.
If you are not using any of the asynchronous clear
options, select Not used and specify whether
registers should power up high or low by turning
on/off Registers power up high.
Synchronous clear and synchronous set ports
Select Use ‘sclr’ port for synchronous clear (sclr).
Select Use ‘sset’ port for synchronous preset (sset).
If you are not using any of the synchronous clear
options, select Not used.
The synchronous reset option is available for
Arria GX, Stratix III, Stratix II, Stratix II GX,
Stratix, Stratix GX, HardCopy II, and HardCopy
Stratix devices only.
Invert ‘padio’ port
The ‘padio’ port is inverted whenever driven as an
output. This option is available for Cyclone III and
Cyclone II devices only.
Use ‘inclocken’ and ‘outclocken’ ports
Turn on this option to add a clock enable port to
control when data input and output are clocked in.
This signal prevents data from being passed
through.
Use output enable port
Turn on this option to create an output enable input
port (
oe
) to control when the data is set out to the
dataout
port.
Use oe_out port to connect to tri-state output
buffer(s)
Output enable for the bidirectional
padio
port. This
port is available for Stratix III and Cyclone III
devices only.
Register ‘oe’ port
Turn on this option to register the output-enable
(
oe
) input port.
Delay switch-on by a half clock cycle
Turn on this option to use an additional
oe
register.
When the additional
oe
register is used, the output
pin is held at high impedance for an extra half clock
cycle after the
oe
port goes high.
Use ‘combout’ port
Use the optional data port
combout
. The
combout
port sends data to the core, bypassing the DDR I/O
input registers. For bidirectional operation, you
must enable the
dataout_h
and
dataout_l
ports,
the
combout
port, or both.
UG-DDRMGAFCTN
2015.01.23
ALTDDIO Parameter Settings
5
Double Data Rate I/O (ALTDDIO_IN, ALTDDIO_OUT, and ALTDDIO_BIDIR) IP Cores User Guide
Altera Corporation