µPD784935A,784936A,784937A,784938A
7.2 CPU Registers
7.2.1 General-purpose registers
Sixteen 8-bit general-purpose registers are available. Two 8-bit general-purpose registers can be used in com-
bination as a 16-bit general-purpose register. Four of the 16-bit registers can be used in combination with an 8-bit
register for address extension as 24-bit address specification registers.
Eight banks of register sets are available, which can be selected by software or using the context switching function.
The general-purpose registers, except registers V, U, T, and W for address extension, are mapped to the internal
RAM.
Figure 7-5. General-Purpose Register Format
A (R1)
X (R0)
AX (RP0)
B (R3)
C (R2)
BC (RP1)
R5
R4
RP2
R7
R6
RP3
V
R9
R8
VVP (RG4)
VP (RP4)
U
R11
R10
UUP (RG5)
UP (RP5)
T
D (R13)
E (R12)
TDE (RG6)
DE (RP6)
W
H (R15)
L (R14)
WHL (RG7)
HL (RP7)
( ): Absolute name
8 banks
Caution R4, R5, R6, R7, RP2, and RP3 can be used as X, A, C, B, AX, and BC registers, respectively, by
setting the RSS bit of PSW to 1. However, use this function only when using a program written
for the 78K/III series.
Data Sheet U13572EJ2V0DS
27