Microcontroller .pptx
- 2. In 8051 There are six types of addressing modes. Register AddressingMode Direct AddressingMode Register IndirectAddressing Mode Immediate AddressingMode Implied/Register Specfic AddressingMode Indexed AddressingMode
- 3. The register addressing instruction involves information transfer between registers The 8051 can access eight ‘’working registers’’(R0- R7). Three bit code within the instruction selects one of the eight registers from the selected register bank. The programmer can select a register bank by modifying bits 4 and 3 in the PSW.
- 4. Example: add the content of register r3 and r4 from bank 2. step 1: MOV PSW step 2:MOV A, R3 MOV A, R4
- 5. Can access any on chip variable and hardware register.(RAM and SF register). This mode allows you to specify the operand by giving its actual memory address. the MSB of the address decides whether it is a location within in the chip RAM(MSB=0) or in SFR.(MSB=1). Example: MOV A,50H ADD A, 51H
- 6. addressing mode R0 and R1 of each register bank can be used as an index or pointer register. R0 and R1 point to the contents in the RAM. the instruction with indirect addressing uses the@ sign. Example: MOV A , @R0 ADD A ,@R1
- 7. In this Immediate Addressing Mode, the data is provided in the instruction itself. The data is provided immediately after the opcode. The sign # indicates it is a immediate addressing mode. Example: MOV A ,#52
- 8. Inherent in the instruction, these refers to a specific register such as accumulator or DPTR. In the implied addressing mode, there will be a single operand. These types of instruction can work on specific registers only. Example: RLA , SWAPA These are 1- byte instruction. The first one is used to rotate the A register content to the Left. The second one is used to swap the nibbles in A.
- 9. Only program memory can be accessed in the index addressing. Either DPTR or PC can be used as an index. Example: MOVCA, @A+PC; MOVCA, @A+DPTR; The C in MOVC instruction refers to code byte. For the first instruction, let us consider A holds 30H. And the PC value is1125H. The contents of program memory location 1155H (30H + 1125H) are moved to register A.
- 10. Comparison b/w MC and MP Features of 8051 Architecture Pin configuration Memory organization(external data and program) Addressing modes
- 11. 8051 microcontrollers are manufactured by which of the following companies? a) Atmel b) Philips c) Intel d) All of the mentioned Unlike microprocessors, microcontrollers make use of batteries because they have: a) high power dissipation b) low power consumption c) low voltage consumption d) low current consumption The internal RAM memory of the 8051 is: A. 32 bytes B. 64 bytes C. 128 bytes D. 256 bytes
- 12. The 8051 has ________ 16-bit counter/timers. A. 1 B. 2 C. 3 D. 4 Microcontrollers often have: A. CPUs B. RAM C. ROM D. all of the above