HD404639R Datasheet, PDF (50/135 Pages) Renesas Technology Corp – 4-Bit Single-Chip Microcomputer

HD404639R Series
Data control register (DCD0 to 2: $02C to $02E)
(DCR0 to C: $030 to $03C)
DCD0 to DCD2
Bit
3
2
1
0
Initial value
0
0
0
0
Read/Write
W
W
W
W
Bit name
DCD03– DCD02– DCD01– DCD00–
DCD23 DCD22 DCD21 DCD20
DCR0 to DCRB
Bit
3
2
1
0
Initial value
0
0
0
0
Read/Write
W
W
W
W
Bit name
DCR03– DCR02– DCR01– DCR00–
DCRB3 DCRB2 DCRB1 DCRB0
DCRC
Bit
3
2
1
0
Initial value
—
—
—
0
Read/Write
—
—
—
W
Bit name
Not used Not used Not used DCRC0
All Bits
0
1
CMOS Buffer On/Off Selection
Off (high-impedance)
On
Correspondence between ports and DCD/DCR bits
Register Name
DCD0
DCD1
DCD2
DCR0
DCR1
DCR2
DCR3
DCR4
DCR5
DCR6
DCR7
DCR8
DCR9
DCRA
DCRB
DCRC
Bit 3
D₃
D₇
D₁₁
R0₃
R1₃
R2₃
R3₃
R4₃
R5₃
R6₃
R7₃
R8₃
R9₃
RA₃
RB₃
—
Bit 2
D₂
D₆
D₁₀
R0₂
R1₂
R2₂
R3₂
R4₂
R5₂
R6₂
R7₂
R8₂
R9₂
RA₂
RB₂
—
Bit 1
D₁
D₅
D₉
R0₁
R1₁
R2₁
R3₁
R4₁
R5₁
R6₁
R7₁
R8₁
R9₁
RA₁
RB₁
—
Bit 0
D₀
D₄
D₈
R0₀
R1₀
R2₀
R3₀
R4₀
R5₀
R6₀
R7₀
R8₀
R9₀
RA₀
RB₀
RC₀
Figure 28 Data Control Registers (DCD, DCR)
48