S3C8245/P8245/C8249/P8249 ADDRESS SPACES
2-3
REGISTER ARCHITECTURE
In the S3C8245/C8249 implementation, the upper 64-byte area of register files is expanded two 64-byte areas, called
set 1 and set 2. The upper 32-byte area of set 1 is further expanded two 32-byte register banks (bank 0 and bank 1),
and the lower 32-byte area is a single 32-byte common area.
In case of S3C8249/P8249 the total number of addressable 8-bit registers is 1122. Of these 1122 registers, 16 bytes
are for CPU and system control registers, 16 bytes are for LCD data registers, 50 bytes are for peripheral control and
data registers, 16 bytes are used as a shared working registers, and 1024 registers are for general-purpose use,
page 0-page 4 (in case of S3C8245/P8245, page 0-page 2).
You can always address set 1 register locations, regardless of which of the four register pages is currently selected.
Set 1 locations, however, can only be addressed using register addressing modes.
The extension of register space into separately addressable areas (sets, banks, and pages) is supported by various
addressing mode restrictions, the select bank instructions, SB0 and SB1, and the register page pointer (PP).
Specific register types and the area (in bytes) that they occupy in the register file are summarized in Table 2–1.
Table 2-1. S3C8249/P8249 Register Type Summary
Register Type Number of Bytes
General-purpose registers (including the 16-byte common
working register area, four 192-byte prime register area,
and four 64-byte set 2 area)
LCD data registers
CPU and system control registers
Mapped clock, peripheral, I/O control, and data registers
1,040
16
16
50
Total Addressable Bytes 1,122
Table 2-2. S3C8245/P8245 Register Type Summary
Register Type Number of Bytes
General-purpose registers (including the 16-byte common
working register area, four 192-byte prime register area,
and four 64-byte set 2 area)
LCD data registers
CPU and system control registers
Mapped clock, peripheral, I/O control, and data registers
528
16
16
50
Total Addressable Bytes 610