LVCMOS

UltraScale Architecture SelectIO Resources User Guide (UG571)

Document ID

UG571

Release Date

2023-08-31

Revision

1.15 English

Table 1-18: Available I/O Bank Type
HR	HP
Available	Available

Low voltage CMOS (LVCMOS) is a widely used switching standard implemented in CMOS transistors. This standard is defined by JESD8-12A.01, JESD8-11A.01, JESD8-7A, JESD8-5A.01, and JESD8C.01 [Ref 7] . The LVCMOS standards supported in UltraScale devices are: LVCMOS12, LVCMOS15, LVCMOS18, LVCMOS25, and LVCMOS33.

Sample circuits illustrating both unidirectional and bidirectional LVCMOS termination techniques are shown in This Figure and This Figure . These two diagrams show examples of source-series and parallel terminated topologies.

This Figure shows unidirectional terminated topologies.

Figure 1-49: LVCMOS Unidirectional Termination
X-Ref Target - Figure 1-49

This Figure shows a bidirectional, parallel-terminated topology.

Figure 1-50: LVCMOS Bidirectional Termination
X-Ref Target - Figure 1-50

Table: Allowed Attributes for the LVCMOS33 and LVCMOS25 I/O Standards details the allowed attributes that can be applied to the LVCMOS33 and LVCMOS25 I/O standards. These standards are only available in the HR I/O banks. Support is implied for primitives that are derivatives of the primitives listed in Table: Allowed Attributes for the LVCMOS33 and LVCMOS25 I/O Standards (for example: *_DIFF_OUT, *_DCIEN, *_IBUFDISABLE, or *_INTERMDISABLE). Refer to the SelectIO Interface Primitives section for all supported derivatives.

Table 1-19: Allowed Attributes for the LVCMOS33 and LVCMOS25 I/O Standards
Attributes	Primitives
	IBUF	OBUF/OBUFT/IOBUF
	IBUF	Allowed Values	Default
IOSTANDARD	LVCMOS33, LVCMOS25	LVCMOS33, LVCMOS25
DRIVE	N/A	4, 8, 12, or 16	12
SLEW	N/A	FAST or SLOW	SLOW

Table: Allowed Attributes for the LVCMOS18 I/O Standard details the allowed attributes that can be applied to the LVCMOS18 I/O standard. This standard is available in both the HR and HP I/O banks. For MOBILE DDR applications, the LVCMOS18 I/O standard is used with an 8 mA unterminated drive. Support is implied for primitives that are derivatives of the primitives listed in Table: Allowed Attributes for the LVCMOS18 I/O Standard (for example: *_DIFF_OUT, *_DCIEN, *_IBUFDISABLE, or *_INTERMDISABLE). Refer to the SelectIO Interface Primitives section for all supported derivatives.

Table 1-20: Allowed Attributes for the LVCMOS18 I/O Standard
Attributes	Primitives
	IBUF	OBUF/OBUFT/IOBUF
		HP I/O Banks		HR I/O Banks
		Allowed Values	Default	Allowed Values	Default
IOSTANDARD	LVCMOS18	LVCMOS18		LVCMOS18
DRIVE	N/A	2, 4, 6, 8, 12	12	4, 8, 12, 16	12
SLEW	N/A	FAST, MEDIUM, SLOW	SLOW	FAST, SLOW	SLOW

Table: Allowed Attributes for the LVCMOS15 I/O Standard details the allowed attributes that can be applied to the LVCMOS15 I/O standard. This standard is available in both the HR and HP I/O banks. Support is implied for primitives that are derivatives of the primitives listed in Table: Allowed Attributes for the LVCMOS15 I/O Standard (for example: *_DIFF_OUT, *_DCIEN, *_IBUFDISABLE, or *_INTERMDISABLE). Refer to the SelectIO Interface Primitives section for all supported derivatives.

Table 1-21: Allowed Attributes for the LVCMOS15 I/O Standard
Attributes	Primitives
	IBUF	OBUF/OBUFT/IOBUF
		HP I/O Banks		HR I/O Banks
		Allowed Values	Default	Allowed Values	Default
IOSTANDARD	LVCMOS15	LVCMOS15		LVCMOS15
DRIVE	N/A	2, 4, 6, 8, 12	12	4, 8, 12, 16	12
SLEW	N/A	FAST, MEDIUM, SLOW	SLOW	FAST, SLOW	SLOW

Table: Allowed Attributes for the LVCMOS12 I/O Standard details the allowed attributes that can be applied to the LVCMOS12 I/O standard. This standard is available in both the HR and HP I/O banks. Support is implied for primitives that are derivatives of the primitives listed in Table: Allowed Attributes for the LVCMOS12 I/O Standard (for example: *_DIFF_OUT, *_DCIEN, *_IBUFDISABLE, or *_INTERMDISABLE). Refer to the SelectIO Interface Primitives section for all supported derivatives.

Table 1-22: Allowed Attributes for the LVCMOS12 I/O Standard
Attributes	Primitives
	IBUF	OBUF/OBUFT/IOBUF
		HP I/O Banks		HR I/O Banks
		Allowed Values	Default	Allowed Values	Default
IOSTANDARD	LVCMOS12	LVCMOS12		LVCMOS12
DRIVE	N/A	2, 4, 6, 8	12 ⁽¹⁾	4, 8, 12	12
SLEW	N/A	FAST, MEDIUM, SLOW	SLOW	FAST, SLOW	SLOW
Notes: 1. Change the drive setting from the default setting in the RTL or XDC file to one of the allowed values before running through the Vivado Design Suite.