UPD78320GJ-5BJ NEC, UPD78320GJ-5BJ Datasheet - Page 24

• Manufacturer Part Number: UPD78320GJ-5BJ
• Description: 16/8-BIT SINGLE-CHIP MICROCONTROLLER
• Manufacturer: NEC

24
the lower half of the 16-bit accumulator, the A register functions as the upper half of the 8-bit or 16-bit accumulator, the B
and C registers function as counters, and DE, HL, VP and UP function as address register pairs. In particular the VP register
functions as a base register and the UP register functions as a user stack pointer.
in the PSW.
of the RSS flag.
importance attached to the unique function of each register and register addressing by absolute names with a view to fast
processing with a small number of data transfers or creating highly descriptive programs.
The sixteen 8-bit registers can function as eight 16-bit register pairs (RP0 to RP7) as well.
As shown in Table 2-1, the sixteen 8-bit registers are characterized by functional names. The X register functions as
The unique function register changes as shown in Table 2-1 according to the value of the register set select flag (RSS)
Thus, if the program is described by the functional name, another register set of X, A, C and B can be used by means
The PD78322 can carry out processed data addressing operations, implied addressing by functional names with
Absolute
Name
R10
R11
R12
R13
R14
R15
R0
R1
R2
R3
R4
R5
R6
R7
R8
R9
RSS = 0
VP
UP
UP
VP
X
A
C
B
E
D
H
L
Functional Name
H
H
L
L
Table 2-1. General Register Configuration
RSS = 1
VP
UP
UP
VP
X
A
C
B
E
D
H
L
H
H
L
L
Absolute
Name
RP0
RP1
RP2
RP3
RP4
RP5
RP6
RP7
RSS = 0
AX
BC
VP
UP
DE
HL
Functional Name
PD78320, 78322
RSS = 1
AX
BC
VP
UP
DE
HL