8051 Memory

• The data width is 8 bits

• Registers are 8 bits

• Addresses are 8 bits

  • i.e. addresses for only 256 bytes!
  • PC is 16 bits (up to 64K program memory)
  • DPTR is 16 bits (for external data - up to 64K)

• C types

  • char - 8 bits <-- use this if at all possible!
  • short - 16 bits
  • int - 16 bits
  • long - 32 bits
  • float - 32 bits

• C standard signed/unsigned

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