Single-Termination DCI

UltraScale Architecture SelectIO Resources User Guide (UG571)

Document ID
UG571
Release Date
2022-08-31
Revision
1.14 English

Some I/O standards (POD10, POD12, HSUL_12, and DIFF_HSUL_12) require an input termination resistance (R) to a VTT voltage of VCCO (see This Figure).

Figure 1-12:      Input Termination to VCCO without DCI (where R = Z0)

X-Ref Target - Figure 1-12

X16070-input-term-to-vcco-without-dci-where-r-is-z0.jpg

The DCI input standards supporting single termination are shown in Table: All DCI I/O Standards Supporting Single-Termination DCI .

Table 1-4:      All DCI I/O Standards Supporting Single-Termination DCI 

POD12_DCI

DIFF_POD12_DCI

HSUL_12_DCI

POD10_DCI

DIFF_POD10_DCI

DIFF_HSUL_12_DCI

Single-termination DCI creates a termination to VCCO internally as shown in This Figure. Value of the termination resistor is determined by the ODT attribute. Possible values for ODT:

POD standards only: RTT_40, RTT_48, and RTT_60

HSUL_12_DCI and DIFF_HSUL_12_DCI only: RTT_120 and RTT_240

RTT_NONE

Figure 1-13:      Input Termination to VCCO using Single-Termination DCI (where R = Z0)

X-Ref Target - Figure 1-13

X16071-input-term-to-vcco-using-single-term-dci-where-r-is-z0.jpg

For example, to achieve single termination of approximately 50W to VCCO for the POD12_DCI standard, a 240W external precision resistor is required at the VRP pin, ODT must be set to the value RTT_48.