Samsung C8278X User Manual
ADDRESS SPACES
S3C8275X/F8275X/C8278X/F8278X/C8274X/F8274X
2-10
REGISTER SET 1
The term set 1 refers to the upper 64 bytes of the register file, locations C0H–FFH.
The upper 32-byte area of this 64-byte space (E0H–FFH) is expanded two 32-byte register banks, bank 0 and
bank 1. The set register bank instructions, SB0 or SB1, are used to address one bank or the other. A hardware
reset operation always selects bank 0 addressing.
bank 1. The set register bank instructions, SB0 or SB1, are used to address one bank or the other. A hardware
reset operation always selects bank 0 addressing.
The upper two 32-byte areas (bank 0 and bank 1) of set 1 (E0H–FFH) contains 48 mapped system and
peripheral control registers. The lower 32-byte area contains 16 system registers (D0H–DFH) and a 16-byte
common working register area (C0H–CFH). You can use the common working register area as a “scratch” area
for data operations being performed in other areas of the register file.
peripheral control registers. The lower 32-byte area contains 16 system registers (D0H–DFH) and a 16-byte
common working register area (C0H–CFH). You can use the common working register area as a “scratch” area
for data operations being performed in other areas of the register file.
Registers in set 1 locations are directly accessible at all times using Register addressing mode. The 16-byte
working register area can only be accessed using working register addressing (For more information about
working register addressing, please refer to Chapter 3, “Addressing Modes.”)
working register area can only be accessed using working register addressing (For more information about
working register addressing, please refer to Chapter 3, “Addressing Modes.”)
REGISTER SET 2
The same 64-byte physical space that is used for set 1 locations C0H–FFH is logically duplicated to add another
64 bytes of register space. This expanded area of the register file is called set 2. For the S3C8275X,
the set 2 address range (C0H–FFH) is accessible on pages 0–1.
S3C8278X/C8274X, the set 2 address range (C0H–FFH) is accessible on page 0.
64 bytes of register space. This expanded area of the register file is called set 2. For the S3C8275X,
the set 2 address range (C0H–FFH) is accessible on pages 0–1.
S3C8278X/C8274X, the set 2 address range (C0H–FFH) is accessible on page 0.
The logical division of set 1 and set 2 is maintained by means of addressing mode restrictions. You can use only
Register addressing mode to access set 1 locations. In order to access registers in set 2, you must use Register
Indirect addressing mode or Indexed addressing mode.
Register addressing mode to access set 1 locations. In order to access registers in set 2, you must use Register
Indirect addressing mode or Indexed addressing mode.
The set 2 register area is commonly used for stack operations.