S3C80A5B
ADDRESS SPACES
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ADDRESS SPACES
OVERVIEW
The S3C80A5B microcontroller has two types of address space:
— Internal program memory (ROM)
— Internal register file
A 16-bit address bus supports program memory operations. A separate 8-bit register bus carries addresses and
data between the CPU and the register file.
The S3C80A5B has an internal 15,872 byte programmable ROM. An external memory interface is not implemented.
The 256-byte physical RAM space is expanded into an addressable area of 320 bytes by the use of addressing
modes.
There are 312 mapped registers in the internal register file. Of these, 272 are for general-purpose use. (This number
includes a 16-byte working register common area that is used as a " scratch area" for data operations, a 256 prime
register area that is used for general purpose and stack operation). Eighteen 8-bit registers are used for CPU and
system control and 22 registers are mapped peripheral control and data registers.