CHAPTER 3 CPU ARCHITECTURE
User’s Manual U18172EJ2V0UD
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3.2.2 General-purpose registers
A general-purpose register consists of eight 8-bit registers (X, A, C, B, E, D, L, and H).
In addition each register being used as an 8-bit register, two 8-bit registers in pairs can be used as a 16-bit register
(AX, BC, DE, and HL).
Registers can be described in terms of function names (X, A, C, B, E, D, L, H, AX, BC, DE, and HL) and absolute
names (R0 to R7 and RP0 to RP3).
Figure 3-12. General-Purpose Register Configuration
(a) Function names
X
15
0
7
0
16-bit processing
8-bit processing
HL
DE
BC
AX
A
C
B
E
D
L
H
(b) Absolute names
R0
15
0
7
0
16-bit processing
8-bit processing
RP3
RP2
RP1
RP0
R1
R2
R3
R4
R5
R6
R7