Ports and Attributes Influencing BISC - Ports and Attributes Influencing BISC - UG861

Spartan UltraScale+ FPGAs SelectIO Resources User Guide (UG861)

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

The following figure highlights the BITSLICE_CONTROL ports and attributes involved in the BISC process.

Table 1. BITSLICE_CONTROL Ports and Attributes for the BISC Process
Pins I/O Type Description
Logic Control
EN_VTC In Data Enable VT tracking.
Status
VTC_RDY Out Data Nibble ready for VT calibration
DLY_RDY Out Data Nibble delay line calibration is complete.
RIU
RIU_CLK In Clock Clock from interconnect logic. The RIU clock must be connected in for the BISC process to complete.
RIU_ADDR[5:0] In Data Register address.
RIU_WR_DATA[15:0] In Data Data write to register.
RIU_RD_DATA[15:0] Out Data Data read from register.
RIU_VALID Out Data Status indicating if BISC is accessing RIU registers.
RIU_WR_EN In Enable Register write enable (active-High).
RIU_NIBBLE_SEL In Data Nibble in byte select. This signal must be High to perform read/write to the nibble.
Attributes
IDLY_VT_TRACK     Enable input delay line VT tracking.
ODLY_VT_TRACK     Enable output delay line VT tracking.
QDLY_VT_TRACK     Enable slave quarter delay VT tracking.
ROUNDING_FACTOR     Value to scale the VT tracking. This attribute has a default value that normally does not need to be changed.
SELF_CALIBRATE     Start a self-calibrate cycle.
RIU Registers     Read the RIU paragraph.