General-Purpose Registers - NEC PD789860 User Manual

4.2.2 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).
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CHAPTER 4 CPU ARCHITECTURE
Figure 4-10. General-Purpose Register Configuration
(a) Absolute names
16-bit processing
RP3
RP2
RP1
RP0
15 0
(b) Function names
16-bit processing
HL
DE
BC
AX
15 0
User's Manual U14826EJ5V0UD
8-bit processing
R7
R6
R5
R4
R3
R2
R1
R0
7 0
8-bit processing
H
L
D
E
B
C
A
X
7 0