carry8

一、carry的构成

二、carry8的例化及端口功能说明

   CARRY8 #(
      .CARRY_TYPE("SINGLE_CY8")  // 8-bit or dual 4-bit carry (DUAL_CY4, SINGLE_CY8)
   )
   CARRY8_inst (
      .CO(CO),         // 8-bit output: Carry-out
      .O(O),           // 8-bit output: Carry chain XOR data out
      .CI(CI),         // 1-bit input: Lower Carry-In
      .CI_TOP(CI_TOP), // 1-bit input: Upper Carry-In
      .DI(DI),         // 8-bit input: Carry-MUX data in
      .S(S)            // 8-bit input: Carry-mux select
   );

三、carry8的内部架构

参考ug574第23页