ice40_wrapcarry - iCE40: wrap carries¶
yosys> help ice40_wrapcarry¶
Wrap manually instantiated SB_CARRY cells, along with their associated SB_LUT4s, into an internal $__ICE40_CARRY_WRAPPER cell for preservation across technology mapping. Attributes on both cells will have their names prefixed with 'SB_CARRY.' or 'SB_LUT4.' and attached to the wrapping cell. A (* keep *) attribute on either cell will be logically OR-ed together.
unwrap $__ICE40_CARRY_WRAPPER cells back into SB_CARRYs and SB_LUT4s, including restoring their attributes.