I/O-Related Constraints - 2022.2 English - UG911

ISE to Vivado Design Suite Migration Guide (UG911)

Document ID
UG911
Release Date
2022-10-19
Version
2022.2 English

IODELAY_GROUP

Applied To

IDELAY and IDELAYCTRL cells

Constraint Values

String

UCF Example

INST idelay0 IODELAY_GROUP = group0;

XDC Example

set_property IODELAY_GROUP group0 [get_cells idelay0]

DCI_VALUE

Applied To

I/O buffer cells

Constraint Values

Integer. Resistance in Ohms

UCF Example

INST a_IBUF[0]_inst DCI_VALUE = 75;

XDC Example

set_property DCI_VALUE 75 [get_cells {a_IBUF[0]_inst}]

DIFF_TERM

Applied To

I/O buffer cells

Constraint Values

Boolean

UCF Example

INST a_IBUF[0]_inst DIFF_TERM = TRUE;

XDC Example

set_property DIFF_TERM true [get_cells {a_IBUF[0]_inst}]

DRIVE

Applied To

Inout and output buffer cells

Constraint Values

Integer: 2, 4, 6, 8, 12, 16, 24

UCF Example

INST q_OBUF[0]_inst DRIVE = 24;

XDC Example

set_property DRIVE 24 [get_ports q[0]]

LVTTL allows a value of 24.

IOSTANDARD

Applied To

I/O buffer cells

Constraint Values

I/O standard string

UCF Example

INST q_OBUF[0]_inst IOSTANDARD = LVCMOS25;

XDC Example

set_property IOSTANDARD LVCMOS25 [get_ports q[0]]

For more information, see the Constraints Guide (UG625) [Ref 11] .

SLEW

Applied To

Inout and output buffer cells

Constraint Values

SLOW or FAST

UCF Example

INST q_OBUF[0]_inst SLEW = FAST;

XDC Example

set_property SLEW FAST [get_ports q[0]]

FAST

Applied To

Inout and output buffer cells

Constraint Values

N/A

UCF Example

INST q_OBUF[0]_inst FAST;

XDC Example

set_property SLEW FAST [get_ports q[0]]

SLOW

Applied To

Inout and output buffer cells

Constraint Values

N/A

UCF Example

INST q_OBUF[0]_inst SLOW;

XDC Example

set_property SLEW SLOW [get_ports q[0]]