Altera ALTPLL (Phase-Locked Loop) IP Core User Manual
Page 60
Description
Type
Parameter
Specifies whether the
fbmimicbidir
port is used. Values
are
ON
or
OFF
. If omitted, the default is
OFF
.
For Stratix III and Stratix IV device families, with the
OPERATION_MODE
parameter set to
ZERO_DELAY_BUFFER
,
and the
USING_FBMIMICBIDIR_PORT
parameter is set to
OFF
, you must perform the following steps:
1. Instantiate an ALT_IOBUF IP core.
2. Connect the
fbout
and
fbin
ports to the
o
and
i
ports
of the ALT_IOBUF instantiation, respectively.
3. Connect the bidirectional port of the ALT_IOBUF
instantiation to a bidirectional pin, and set the
oe
port
of the ALT_IOBUF instantiation to
1
.
If the
OPERATION_MODE
parameter is set to
ZERO_DELAY_
BUFFER
, and the
USING_FBMIMICBIDIR_PORT
parameter is
set to
ON
, connect the
fbmimicbidir
port to a bidirectional
pin. This pin must be placed on the positive feedback
dedicated output pin of the PLL.
String
USING_FBMIMICBIDIR_PORT
Specifies the scaling factor, in half-clock cycles, for which
the clock output ports must be locked before the locked
pin goes high.
Integer
VALID_LOCK_MULTIPLIER
Specifies the center value for the VCO pin. Use for
simulation purposes only.
Integer
VCO_CENTER
Specifies the integer division factor for the VCO pin. If
omitted, the default is
0
. If
VCO_FREQUENCY_CONTROL
is set
to
MANUAL_PHASE
, specify the VCO frequency as a phase
shift step value; that is, one-eighth of the VCO period.
Integer
VCO_DIVIDE_BY
Specifies the integer division factor for the VCO pin. If
omitted, the default is
0
. If
VCO_FREQUENCY_CONTROL
is set
to
MANUAL_PHASE
, specify the VCO frequency as a phase
shift step value; that is, one-eighth of the VCO period.
Specifies the frequency control value for the VCO pin.
Values are
AUTO
,
MANUAL_FREQUENCY
, and
MANUAL_PHASE
.
If omitted, the default is
AUTO
.
•
AUTO
—
VCO_MULTIPLY_BY
and
VCO_DIVIDE_BY
values
are ignored and VCO frequency is set automatically.
•
MANUAL_FREQUENCY
—Specifies the VCO frequency as
a multiple of the input frequency.
•
MANUAL_PHASE
—Specifies the VCO frequency as a phase
shift step value.
String
VCO_FREQUENCY_CONTROL
Specifies the maximum value for the VCO pin. Use for
simulation purposes only.
Integer
VCO_MAX
ALTPLL (Phase-Locked Loop) IP Core User Guide
Altera Corporation
ug-altpll
ALTPLL Parameters
60
2014.08.18