{"id":1568,"date":"2020-03-30T04:02:52","date_gmt":"2020-03-30T04:02:52","guid":{"rendered":"https:\/\/bcisnotes.com\/thirdsemester\/?p=1568"},"modified":"2020-03-30T04:10:10","modified_gmt":"2020-03-30T04:10:10","slug":"arithmetic-operations","status":"publish","type":"post","link":"https:\/\/bcisnotes.com\/thirdsemester\/computer-architecture-and-microprocessor\/arithmetic-operations\/","title":{"rendered":"Arithmetic Operations || 8085 Microprocessor || BcisNotes"},"content":{"rendered":"

Arithmetic Operations<\/h2>\n

The 8085 microprocessor performs various arithmetic operations, such as addition, subtraction, increment, and decrement. These arithmetic operations have the following mnemonics.<\/p>\n

INTRODUCTION TO 8085 ARITHMETIC INSTRUCTIONS<\/strong><\/p>\n\n\n\n\n\n\n\n\n
\u00a0ADD:<\/td>\nAdd<\/td>\nAdd the contents of a register.<\/td>\n<\/tr>\n
\u00a0ADI:<\/td>\nAdd Immediately<\/td>\nAdd 8-bit data.<\/td>\n<\/tr>\n
\u00a0SUB:<\/td>\nSubtract<\/td>\nSubtract the contents of a register.<\/td>\n<\/tr>\n
\u00a0SUI:<\/td>\nSubtract Immediately<\/td>\nSubtract 8-bit data.<\/td>\n<\/tr>\n
\u00a0INR:<\/td>\nIncrement<\/td>\nIncrease the content of register by1.<\/td>\n<\/tr>\n
\u00a0DCR:<\/td>\nDecrement<\/td>\nDecrease the content of register by1.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

The arithmetic operations ADD and Subtract are performed in relation to the contents of the accumulator. However, the Increment or the Decrement operations can be performed in any register. The instructions for these operations are explained below:<\/p>\n

INSTRUCTIONS<\/strong><\/p>\n

These arithmetic instructions(except INR and DCR)<\/p>\n

    \n
  1. assume implicitly that the accumulator is one of the operands.<\/li>\n
  2. modify all the flags according to the data conditions of the result.<\/li>\n
  3. place the result in the accumulator.<\/li>\n
  4. do not affect the contents of the operand register.<\/li>\n<\/ol>\n

    The instructions INR and DCR<\/p>\n

      \n
    1. affects the content of the specified register.<\/li>\n
    2. affect all flags expect the CY flag.<\/li>\n<\/ol>\n

      The descriptions of the instructions (including INR and DCR) are as follows:<\/p>\n\n\n\n\n\n\n\n\n\n
      Opcode<\/strong><\/td>\nOperand<\/strong><\/td>\nDescription<\/strong><\/td>\n<\/tr>\n
      \u00a0 ADD<\/strong><\/td>\nR<\/td>\nADD<\/p>\n
        \n
      • This is 1-byte instructions.<\/li>\n
      • Adds the contents of register R to the contents of the accumulator.<\/li>\n<\/ul>\n<\/td>\n<\/tr>\n
      \u00a0 ADI<\/strong><\/td>\n8-bit<\/td>\nAdd Immediately<\/p>\n
        \n
      • This is 2-byte instructions.<\/li>\n
      • Adds the second byte to the contents of the accumulator<\/li>\n<\/ul>\n<\/td>\n<\/tr>\n
      \u00a0 SUB<\/strong><\/td>\nR+<\/td>\nSubtract<\/p>\n
        \n
      • This is 1-byte instructions.<\/li>\n
      • Subtract the contents of register R from the contents of the accumulator.<\/li>\n<\/ul>\n<\/td>\n<\/tr>\n
      \u00a0 SUI<\/strong><\/td>\n8-bit<\/td>\nSubtract Immediately<\/p>\n
        \n
      • This is 2-byte instructions.<\/li>\n
      • Subtracts the byte from the contents of the accumulator.<\/li>\n<\/ul>\n<\/td>\n<\/tr>\n
      \u00a0 INR<\/strong><\/td>\nR*<\/td>\nIncrement<\/p>\n
        \n
      • This is 1-byte instructions.<\/li>\n
      • Increases the contents of register R by 1
        \nCaution:\u00a0<\/em><\/strong>All flags except the CY are affected<\/li>\n<\/ul>\n<\/td>\n<\/tr>\n
      \u00a0DCR<\/strong><\/td>\nR*<\/td>\nDecrement<\/p>\n