Memory Map layout for mcs51

It is critical to understand the memory layout of the MCS51 architecture to program the device. Intel originally came out with a processor called 8031,8051,8751,8052. The 8051 had built in ROM for code memory, while the 8031,at89c51 was for use with external code memory(eproms). The 8731 has the eprom and erase window built in. This original chip has 128 bytes of built in data memory. This is called the direct memory.