CHAPTER 3 CPU ARCHITECTURE
3.2.2 General-purpose registers
The general-purpose registers consist of eight 8-bit registers (X, A, C, B, E, D, L, and H).
Each register can be used as an 8-bit register, or two 8-bit registers in pairs can be used as a 16-bit register (AX,
BC, DE, and HL).
General-purpose registers can be described in terms of function names (X, A, C, B, E, D, L, H, AX, BC, DE, or
HL) or absolute names (R0 to R7 and RP0 to RP3).
Figure 3-18. General-Purpose Register Configuration
(a) Absolute names
16-bit processing
RP3
8-bit processing
R7
R6
R5
R4
RP2
RP1
RP0
R3
R2
R1
R0
15
0
7
0
(b) Function names
16-bit processing
HL
8-bit processing
H
L
D
E
DE
BC
AX
B
C
A
X
15
0
7
0
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User’s Manual U15075EJ1V0UM00
NEC [ NEC ]
