S3C8275X/F8275X/C8278X/F8278X/C8274X/F8274X ADDRESS SPACES
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2 ADDRESS SPACES
OVERVIEW
The S3C8275X/C8278X/C8274X 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 S3C8275X has an internal 16-Kbyte mask-programmable ROM. The S3C8278X has an internal 8-Kbyte
mask-programmable ROM. The S3C8274X has an internal 4-Kbyte mask-programmable ROM.
The 256-byte physical register space is expanded into an addressable area of 320 bytes using addressing
modes.
A 16-byte LCD display register file is implemented.
There are 605 mapped registers in the internal register file. Of these, 528 are for general-purpose.
(This number includes a 16-byte working register common area used as a “scratch area” for data operations, two
192-byte prime register areas, and two 64-byte areas (Set 2)). Thirteen 8-bit registers are used for the CPU and
the system control, and 48 registers are mapped for peripheral controls and data registers. Nineteen register
locations are not mapped.