HD404344R Datasheet, PDF (23/102 Pages) Renesas Technology Corp – 4-bit microcomputer has an A/D converter

HD404344R Series/HD404394 Series
Functional Description
Registers and Flags
The CPU has nine registers and two flags. Their configurations are shown in figure 7 and explained as
follows.
Accumulator
Initial value: Undefined, R/W
3
0
(A)
B register
W register
X register
Y register
Initial value: Undefined, R/W
Initial value: Undefined, R/W
Initial value: Undefined, R/W
Initial value: Undefined, R/W
3
0
(B)
10
(W)
3
0
(X)
3
0
(Y)
SPX register
Initial value: Undefined, R/W
SPY register
Initial value: Undefined, R/W
Carry
Initial value: Undefined, R/W
3
0
(SPX)
3
0
(SPY)
0
(CA)
0
Status
Initial value: 1, no R/W
(ST)
Program counter
13
Initial value: 0,
no R/W
Stack pointer
Initial value: $3FF, no R/W
0
(PC)
9
5
0
1 11 1
(SP)
Figure 7 Registers and Flags
21