ODELAYE3 Attributes - ODELAYE3 Attributes - UG861

Spartan UltraScale+ FPGAs SelectIO Resources User Guide (UG861)

Document ID
UG861
Release Date
2026-04-28
Revision
1.1 English

The following table lists the ODELAYE3 attributes.

Table 1. ODELAYE3 Attributes
Attribute Values Default Type Description
CASCADE

NONE

MASTER

SLAVE_MIDDLE

SLAVE_END

NONE String For more information, see CASCADE Attribute.
DELAY_TYPE

FIXED

VAR_LOAD

VARIABLE

FIXED String The DELAY_TYPE attribute sets the type of delay used, it can be FIXED, VARIABLE, or VAR_LOAD. See the DELAY_TYPE Attribute for further information.
DELAY_VALUE

0–1100 (TIME)

0 Decimal

TIME mode: Desired value in ps. Spartan UltraScale+ devices support up to 1.1 ns.

COUNT mode: Desired value in taps.

For more information, see DELAY_VALUE Attribute.

REFCLK_FREQUENCY

300.00–800.00 (IDELAYCTRL)

300.00–2666.67 (BITSLICE_CONTROL)

300.0 1 significant digit float The REFCLK_FREQUENCY attribute specifies the reference clock of the IDELAYCTRL frequency in MHz. This attribute must mimic the clock frequency applied at the IDELAYCTRL component except when DELAY_FORMAT is set to COUNT, in which case the attribute can be left at the default value.
DELAY_FORMAT

TIME 1

COUNT

TIME String

When set to TIME, the delay equals the value given in DELAY_VALUE, specified in ps, and is calibrated by the IDELAYCTRL primitive using the REFCLK port input.

The IDELAYCTRL.REFCLK must be reflected in the ODELAY attribute REFCLK_FREQUENCY.

When set to COUNT, the initial tap setting goes to whatever number of taps is specified in DELAY_VALUE.

This does not give a constant delay because the tap delays vary with PVT. The number of taps in the delay line is important in COUNT mode.

For more information, see DELAY_FORMAT Attribute.

UPDATE_MODE

ASYNC

SYNC

MANUAL

ASYNC String For more information, see UPDATE_MODE Attribute.
SIM_DEVICE ULTRASCALE_PLUS ULTRASCALE String Sets the device version (ULTRASCALE_PLUS)
  1. When in TIME mode, calibration affects the availability of bit slices within the nibble. See HP I/O Bank Overview for more information.