51单片机存储器

51单片机存储空间一览：

Program Memory

Program (CODE) memory is read only; it cannot be written to. Program memory may reside within the 8051 MCU, it may be external, or it may be both, depending upon the 8051 derivative and the hardware design.

• The 8051 architecture supports up to 64K Bytes of program memory. However, program space can be expanded using code banking.
• Some devices offer a larger code space.
• Program code, including all functions and library routines, is stored in program memory.
• Constant variables may also be stored in program memory.
• The 8051 executes programs stored in program memory only.
• Program memory may be accessed from your C programs using the code memory type specifier.

程序存储器

代码空间是只读空间; 它不能被写入修改. 代码存储可能存放于8051微处理器的内部或者外部，也有可能两者都有，这要根据8051具体设计架构以及其硬件设计来决定。

• 8051架构支持高达64K字节的程序存储器空间。然而，程序存储器可以通过使用代码块的方式扩展。
• 一些设备会提供更大的程序存储器空间
• 程序代码（包括所有函数和库例程）存储在程序存储器中。
• 常量存储在程序存储器中。
• 8051仅执行存储在程序存储器中的程序。
• 程序存储器可以使用代码存储器类型说明符C程序进行访问。

Internal Data Memory

Internal data memory resides within the 8051 MCU and is read/write. Up to 256 bytes of internal data memory are available depending upon the 8051 derivative. The first 128 bytes of internal data memory are both directly and indirectly addressable. The upper 128 bytes of data memory (from 0x80 to 0xFF) can be addressed only indirectly (this address space, when accessed dire