NEC PD789488, PD789489, PD78F9488, PD78F9489 - page 61

CHAPTER 3 CPU ARCHITECTURE
User’s Manual U15331EJ4V1UD 61
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 3-14. General-Purpose Register Configuration
(a) Absolute names
R0
15 0 7 0
16-bit processing 8-bit processing
RP3
RP2
RP1
RP0 R1
R2
R3
R4
R5
R6
R7
(b) Function names
X
15 0 7 0
16-bit processing 8-bit processing
HL
DE
BC
AX A
C
B
E
D
L
H