Carry Look-Ahead Logic Primitives

Versal ACAP Configurable Logic Block Architecture Manual (AM005)
Document ID
AM005
Release Date
2023-02-28
Revision
1.2 English

One primitive is available for the carrylookahead8 which containsonly carry look-ahead multiplexers. The following functions are pushed into the LUTS: SUM XOR, CIN multiplexers, and Carry propagation multiplexers.

Figure 1. Carry Look-Ahead Logic Primitive

Attributes

Table 1. Attribute Name, Description, and Possible Values
Attribute Description Values
LOOKB If TRUE, enable LOOKAHEAD to bring carry results from last stage. TRUE or FALSE
LOOKD If TRUE, enable LOOKAHEAD to bring carry results from last stage. TRUE or FALSE
LOOKF If TRUE, enable LOOKAHEAD to bring carry results from last stage. TRUE or FALSE
LOOKH If TRUE, enable LOOKAHEAD to bring carry results from last stage. TRUE or FALSE

Port Descriptions

Table 2. Port Name, Type, and Description
Port Type Description
COUTB Output Output of CLA multiplexer.
COUTD Output Output of CLA multiplexer.
COUTF Output Output of CLA multiplexer.
COUTH Output Output of CLA multiplexer.
CYA Input Input of CLA multiplexer.
CYB Input Input of CLA multiplexer.
CYC Input Input of CLA multiplexer.
CYD Input Input of CLA multiplexer.
CYE Input Input of CLA multiplexer.
CYF Input Input of CLA multiplexer.
CYG Input Input of CLA multiplexer.
CYH Input Input of CLA multiplexer.
PROPA Input Input of CLA multiplexer.
PROPB Input Input of CLA multiplexer.
PROPC Input Input of CLA multiplexer.
PROPD Input Input of CLA multiplexer.
PROPE Input Input of CLA multiplexer.
PROPF Input Input of CLA multiplexer.
PROPG Input Input of CLA multiplexer.
PROPH Input Input of CLA multiplexer.
CIN Input Input of CLA multiplexer.