Program Counter (PC)
- The only register that is not memory mapped in 8051.
- Size: 16-bit.
- Always points to the address of the next instruction to be executed.
- After execution of one instruction PC is incremented to point to the address of the next instruction to be executed.
- PC will increase automatically.
- The content of PC will be placed on the address bus to find and fetch the desired instruction.
- User cannot write in PC.
- Since PC is 16-bit 8051 can access program address from 0x0000 to 0xFFFF, up to 64K bytes.
- After reset, PC always points to 0x0000 of program memory and is incremented each time an instruction is executed.
- The first instruction must be placed at 0x0000 of Program memory.
Related topics:
8051 Registers | 8051 R Registers | 8051 SFR | 8051 P Registers | 8051 Stack | 8051 Stack Pointer | 8051 Data Pointer | 8051 PCON Register | 8051 TCON Register | 8051 TMOD Register | 8051 Timer Registers | 8051 SCON Register | 8051 SBUF Register | 8051 IE Register | 8051 IP Register | 8051 PSW Register | 8051 A Register | 8051 B Register
List of topics: 8051
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