HD404618 Datasheet, PDF (13/89 Pages) Hitachi Semiconductor – 4-Bit Single-Chip Microcomputer

HD404618 Series
Functional Description
Registers and Flags
The MCU has ten registers and two flags for CPU operations. They are illustrated in figure 6 and described
below.
3
0
A
Accumulator
3
0
B
B register
0
V _{V register}
10
W _{W register}
3
0
X
X register
3
0
Y
Y register
3
0
SPX
SPX register
3
SPY
0
SPY register
0
CA _{Carry flag}
0
ST _{Status flag}
13
0
PC
9
5
Program counter
0
11 11
SP
Stack pointer
Figure 6 Registers and Flags
Accumulator (A), B Register (B): Four-bit registers used to hold results from the arithmetic logic unit
(ALU) and transfer data between memory, I/O, and other registers.
13