HD404849 Datasheet, PDF (49/125 Pages) Hitachi Semiconductor – 4-Bit Single-Chip Microcomputer

HD404849 Series
Data control register (DCD0 to DCD2: $02C to $02E)
(DCR0 to DCR7: $030 to $037)
DCD0, DCD1
Bit
3
2
1
0
Initial value
0
0
0
0
Read/Write
W
W
W
W
Bit name
DCD03, DCD02, DCD01, DCD00,
DCD13 DCD12 DCD11 DCD10
DCD2
Bit
3
2
1
0
Initial value
—
—
—
0
Read/Write
—
—
—
W
Bit name
Not used Not used Not used DCD20
DCR0 to DCR3, DCR6, DCR7
Bit
3
2
1
0
Initial value
0
0
0
0
Read/Write
W
W
W
W
Bit name
DCR03– DCR02– DCR01– DCR00–
DCR33 DCR32 DCR31 DCR30
DCR63– DCR62– DCR61– DCR60–
DCR73 DCR72 DCR71 DCR70
All Bits
0
1
CMOS Buffer On/Off Selection
Off (high-impedance)
On
Correspondence between ports and DCD/DCR bits
Register Name
Bit 3
Bit 2
DCD0
DCD1
DCD2
D₃
D₂
D₇
D₆
—
—
DCR0
DCR1
DCR2
DCR3
DCR6
DCR7
R0₃
R0₂
R1₃
R1₂
R2₃
R2₂
R3₃
R3₂
R6₃
R6₂
R7₃
R7₂
Bit 1
D₁
D₅
—
R0₁
R1₁
R2₁
R3₁
R6₁
R7₁
Bit 0
D₀
D₄
D₈
R0₀
R1₀
R2₀
R3₀
R6₀
R7₀
Figure 29 Data Control Registers (DCD, DCR)
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