The 8052 microcontroller is an enhanced version of the 8051. One of the new features of the 8052 is an extra 128 bytes of on-chip RAM space. In other words, the 8051 has only 128 bytes of on-chip RAM, while the 8052 has 256 bytes of it. The 8052 has another 128 bytes of on-chip RAM with addresses 80 – FFH. This extra 128 bytes of on-chip RAM is often called upper memory. he address space 80 – FFH is the same address space assigned to the SFRs. In other words, they are physically two separate memories, but they have the same addresses. This parallel address space in the 8052 forces us to use two different addressing modes to access upper memory.
To access the SFRs, we use direct addressing mode. To access the upper 128 bytes, we use the indirect addressing mode, which uses R0 and R1 registers as pointers.
To access the SFRs, we use direct addressing mode. To access the upper 128 bytes, we use the indirect addressing mode, which uses R0 and R1 registers as pointers.
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8051 Crystal and Baudrate | 8051 Serial Baudrate Calculation | 8051 Timer Delay Calculation | 8051 Software Development Tools | 8051 Development Boards and Evaluation Kits | 8051 Features | 8051 History
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