Datasheet

Register Block
M68HC12B Family Data Sheet, Rev. 9.1
40 Freescale Semiconductor
2.2 Registers
Addr. Register Name Bit 7654321Bit 0
$0000
Port A Data Register
(PORTA)
See page 86.
Read:
PA7 PA6 PA5 PA4 PA3 PA2 PA1 PA0
Write:
Reset:UUUUUUUU
$0001
Port B Data Register
(PORTB)
See page 87.
Read:
PB7 PB6 PB5 PB4 PB3 PB2 PB1 PB0
Write:
Reset:UUUUUUUU
$0002
Data Direction Register A
(DDRA)
See page 86.
Read:
DDA7 DDA6 DDA5 DDA4 DDA3 DDA2 DDA1 DDA0
Write:
Reset:00000000
$0003
Data Direction Register B
(DDRB)
See page 87.
Read:
DDB7 DDB6 DDB5 DDB4 DDB3 DDB2 DDB1 DDB0
Write:
Reset:00000000
$0004 Reserved R R R R R R R R
↓
$0007 Reserved R R R R R R R R
$0008
Port E Data Register
(PORTE)
See page 88.
Read:
PE7 PE6 PE5 PD4 PD3 PD2 PD1 PD0
Write:
Reset:00000000
$0009
Data Direction Register E
(DDRE)
See page 88.
Read:
DDE7 DDE6 DDE5 DDE4 DDE3 DDE2
00
Write:
Reset:00001000
$000A
Port E Assignment Register
(PEAR)
See page 89.
Read:
NDBE
CGMTE
PIPOE NECLK LSTRE RDWE
00
Write:
Reset:10010000
$000B
Mode Register
(MODE)
See page 78.
Read:
SMODN MODB MODA ESTR IVIS EBSWAI 0 EME
Write:
Reset:00011001
$000C
Pullup Control Register
(PUCR)
See page 91.
Read: 0 0 0
PUPE
00
PUPB PUPA
Write:
Reset:00010000
$000D
Reduced Drive Register
(RDRIV)
See page 92.
Read:0000
RDPE
0
RDPB RDPA
Write:
Reset:00000000
$000E Reserved R R R R R R R R
$000F Reserved R R R R R R R R
= Unimplemented R = Reserved U = Unaffected
Notes:
1. Available only on MC68HC912B32 and MC68HC912BC32 devices.
2. Available only on MC68HC912B32 and MC68HC12BE32 devices.
3. Available only on MC68HC(9)12BC32 devices.
Figure 2-1. Register Map (Sheet 1 of 19)