![Once Around the Pins
Power: VCC,VSS (GND)
Reset:RST
Crystal:XTAL1,2
External Device Interfacing: EA,ALE,PSEN,WR,RD
I/O Port: P0-P3 [7:0]
P3: Shared with control lines: Serial RxD TxD, Counter
control T0, T1, External Interrupts INT0, INT1
P0 and P2 are multiplexed with data bus.
P1 can only be used as I/O port.](https://image.slidesharecdn.com/microc-lab1introto8051-161113182619/85/Micro-c-lab1-intro-to-8051-5-320.jpg)
Micro c lab1(intro to 8051)
- 1. INTRODUCTION TO THE CONTROLLER AT89C51 (8051)
- 2. Objectives of the Lab To learn the functionality of different ports and pins of 8051 µcontroller. To discuss the circuits that make 8051 works. To learn the ‘KEIL’ software to create a ‘HEX’ file for the 8051 controller.
- 3. Pins and Ports of 8051 Use with caution If EA high
- 4. Internal Block Diagram of 8051
- 5. Once Around the Pins Power: VCC,VSS (GND) Reset:RST Crystal:XTAL1,2 External Device Interfacing: EA,ALE,PSEN,WR,RD I/O Port: P0-P3 [7:0] P3: Shared with control lines: Serial RxD TxD, Counter control T0, T1, External Interrupts INT0, INT1 P0 and P2 are multiplexed with data bus. P1 can only be used as I/O port.
- 6. Circuits that make 8051 work 2 mc
- 7. Crystal Frequency and Machine Cycle Crystal Frequency used is 11.0592MHz or 11059200 Hz. The oddball frequency is used to synchronize the serial baud rates. At this frequency, the time period of one wave will be 1/11059200 seconds. The ‘time unit’ for 8051 is known as Machine Cycle. And one machine cycle equals 12 waves of crystal frequency. So the time period of 1 machine cycle will be 12 times the time-period of one wave i.e. 12/11059200 sec This comes out to be approximately 1.085 µs.
- 8. Logic Levels & Ports for I/O Operation Always write ‘high’ to ports for input
- 9. Program Structure (Directives) org 00h Coding instructions here delay: ;subroutine ret end
- 10. Registers (Naming) Normally Used Accumulator (A or ACC) Base (B) Ports (P0,P1,P2,P3 & Px.y) PSW (For Flags & Register Banks) R0,R1,…,R7 SP(Stack Pointer) DPTR(Data Pointer) Timer Registers Serial Port Registers Interrupt Registers PCON (Power Control Register) IP (Instruction Pointer) Legend: * Frequently used * Special Functions * Occasionally * Used automatically
- 11. How to work with ‘KEIL’ 1. Locate the ‘Keil uVision2’ icon on the screen. 2. Run the program and go to Project>Close Project if a previous project file is open otherwise go to Project> New Project. 3. The program will ask for the file name. Give any location in the directory and write any program name you like. (Remember: Create a folder before creating program) 4. After step 3, another window will open namely ‘Select Device for Target’. Expand Atmel and click ‘AT89c51’. Also check ‘ Use extended linker LX51 instead of BL51’ and click ‘OK’
- 12. How to work with ‘KEIL’ 5. Now create a new file. Go to File>New. 6. Save this file by any name but give the extension ‘.asm’ e.g. firstprog.asm. 7. On the leftmost side, expand ‘Target1’ to ‘Source Group 1’. Right click on ‘Source Group1’ and select ‘Add files to Group’. A window will appear. Select file type ‘Asm Source File’ and add the just made file and close the window.
- 13. How to work with ‘KEIL’ 9. Now go to Project>Options for Target. A new window will appear. On the ‘Target tab’, modify the xtal frequency to 11.0592. Then go to ‘Output tab’ and check ‘Create HEX File’. 10. Then write the code for the program. After writing code, save it. Then go to Project>Build Target. In the lower box, if there are no errors in the file, ‘creating hex file’ will be written. This means the HEX file is created.
- 14. Lab Task Create HEX file of a blank program.