Datasheet

Monitor ROM
MC68HC908KX8 • MC68HC908KX2 • MC68HC08KX8 Data Sheet, Rev. 2.1
Freescale Semiconductor 25
Addr.Register Name Bit 7654321Bit 0
$0000
Port A Data Register
(PTA)
See page 106.
Read: 0 0 0
PTA4 PTA3 PTA2 PTA1 PTA0
Write:
Reset: Unaffected by reset
$0001
Port B Data Register
(PTB)
See page 108.
Read:
PTB7 PTB6 PTB5 PTB4 PTB3 PTB2 PTB1 PTB0
Write:
Reset: Unaffected by reset
$0002 Unimplemented
$0003 Unimplemented
$0004
Data Direction Register A
(DDRA)
See page 106.
Read: 0 0 0
DDRA4 DDRA3 DDRA2 DDRA1 DDRA0
Write:
Reset:00000000
$0005
Data Direction Register B
(DDRB)
See page 109.
Read:
DDRB7 DDRB6 DDRB5 DDRB4 DDRB3 DDRB2 DDRB1 DDRB0
Write:
Reset:00000000
$0006
↓
$000C
Unimplemented
$000D
Port A Input Pullup Enable
Register (PTAPUE)
See page 108.
Read: 0 0 0
PTAPUE4 PTAPUE3 PTAPUE2 PTAPUE1 PTAPUE0
Write:
Reset:00000000
$000E
↓
$0012
Unimplemented
$0013
SCI Control Register 1
(SCC1)
See page 125.
Read:
LOOPS ENSCI TXINV M WAKE ILTY PEN PTY
Write:
Reset:00000000
$0014
SCI Control Register 2
(SCC2)
See page 127.
Read:
SCTIE TCIE SCRIE ILIE TE RE RWU SBK
Write:
Reset:00000000
$0015
SCI Control Register 3
(SCC3)
See page 129.
Read: R8
T8 R R ORIE NEIE FEIE PEIE
Write:
Reset:UU000000
$0016
SCI Status Register 1
(SCS1)
See page 130.
Read: SCTE TC SCRF IDLE OR NF FE PE
Write:
Reset:11000000
= Unimplemented R = Reserved U = Unaffected
Figure 2-2. Control, Status, and Data Registers (Sheet 1 of 5)