Electronic Circuits and Tutorials
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8051/8052 Microcontroller Tutorial
8051 / 8052 Microcontroller Instruction Set :
AJMP - Absolute Jump
Operation: | AJMP |
Function: | Absolute Jump Within 2K Block |
Syntax: | AJMP code address |
Instructions | OpCode | Bytes | Cycles | Flags |
AJMP page0 | 0x01 | 2 | 2 | None |
AJMP page1 | 0x21 | 2 | 2 | None |
AJMP page2 | 0x41 | 2 | 2 | None |
AJMP page3 | 0x61 | 2 | 2 | None |
AJMP page4 | 0x81 | 2 | 2 | None |
AJMP page5 | 0xA1 | 2 | 2 | None |
AJMP page6 | 0xC1 | 2 | 2 | None |
AJMP page7 | 0xE1 | 2 | 2 | None |
Description: AJMP unconditionally jumps to the indicated code address. The new value for the Program Counter is calculated by replacing the least-significant-byte of the Program Counter with the second byte of the AJMP instruction, and replacing bits 0-2 of the most-significant-byte of the Program Counter with 3 bits that indicate the page of the byte following the AJMP instruction. Bits 3-7 of the most-significant-byte of the Program Counter remain unchanged.
Since only 11 bits of the Program Counter are affected by AJMP, jumps may only be made to code located within the same 2k block as the first byte that follows AJMP.
See Also: LJMP, SJMP, Instruction Set