
I/O Section
MC68HC908AZ60A MC68HC908AS60A MC68HC908AS60E Data Sheet, Rev. 6
Freescale Semiconductor
39
2.2 I/O Section
Addresses $0000–$004F, shown in
Figure 2-2, contain the I/O Data, Status, and Control Registers.
Addr.
Register Name
Bit 7
6
5432
1
Bit 0
$0000
Port A Data Register
(PTA)
Read:
PTA7
PTA6
PTA5
PTA4
PTA3
PTA2
PTA1
PTA0
Write:
$0001
Port B Data Register
(PTB)
Read:
PTB7
PTB6
PTB5
PTB4
PTB3
PTB2
PTB1
PTB0
Write:
$0002
Port C Data Register
(PTC)
Read:
0
PTC5
PTC4
PTC3
PTC2
PTC1
PTC0
Write:
R
$0003
Port D Data Register
(PTD)
Read:
PTD7
PTD6
PTD5
PTD4
PTD3
PTD2
PTD1
PTD0
Write:
$0004
Data Direction Register A
(DDRA)
Read:
DDRA7
DDRA6
DDRA5
DDRA4
DDRA3
DDRA2
DDRA1
DDRA0
Write:
$0005
Data Direction Register B
(DDRB)
Read:
DDRB7
DDRB6
DDRB5
DDRB4
DDRB3
DDRB2
DDRB1
DDRB0
Write:
$0006
Data Direction Register C
(DDRC)
Read:
MCLKEN
0
DDRC5
DDRC4
DDRC3
DDRC2
DDRC1
DDRC0
Write:
R
$0007
Data Direction Register D
(DDRD)
Read:
DDRD7
DDRD6
DDRD5
DDRD4
DDRD3
DDR2
DDRD1
DDRD0
Write:
$0008
Port E Data Register
(PTE)
Read:
PTE7
PTE6
PTE5
PTE4
PTE3
PTE2
PTE1
PTE0
Write:
$0009
Port F Data Register
(PTF)
Read:
0
PTF6
PTF5
PTF4
PTF3
PTF2
PTF1
PTF0
Write:
R
$000A
Port G Data Register
(PTG)
Read:
0000
0
PTG2
PTG1
PTG0
Write:
RRRR
R
$000B
Port H Data Register
(PTH)
Read:
0000
0
PTH1
PTH0
Write:
RRRR
RR
$000C
Data Direction Register E
(DDRE)
Read:
DDRE7
DDRE6
DDRE5
DDRE4
DDRE3
DDRE2
DDRE1
DDRE0
Write:
$000D
Data Direction Register F
(DDRF)
Read:
0
DDRF6
DDRF5
DDRF4
DDRF3
DDRF2
DDRF1
DDRF0
Write:
R
$000E
Data Direction Register G
(DDRG)
Read:
0000
0
DDRG2
DDRG1
DDRG0
Write:
RRRR
R
$000F
Data Direction Register H
(DDRH)
Read:
0000
0
DDRH1
DDRH0
Write:
RRRR
RR
= Unimplemented
R
= Reserved
Figure 2-2. I/O Data, Status and Control Registers (Sheet 1 of 5)