S3C8245/P8245/C8249/P8249 ADDRESS SPACES
2-15
Together they create an
8-bit register address
Register pointer
provides five
high-order bits
Address OPCODE
Selects
RP0 or RP1
RP1
RP0
4-bit address
provides three
low-order bits
Figure 2-11. 4-Bit Working Register Addressing
Register
address
(76H)
RP0
0 1 1 1 0 0 0 0
0 1 1 1 0 1 1 0
R6
0 1 1 0 1 1 1 0
Selects RP0
Instruction
'INC R6'
OPCODE
RP1
0 1 1 1 1 0 0 0
Figure 2-12. 4-Bit Working Register Addressing Example