MC68HC912BD32CFU10 FREESCALE [Freescale Semiconductor, Inc], MC68HC912BD32CFU10 Datasheet - Page 62

• Manufacturer Part Number: MC68HC912BD32CFU10
• Description: Advance Information
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

PORTE — Port E Register
DDRB — Port B Data Direction Register
Bus Control and Input/Output
MC68HC912BD32 Rev 1.0
Single Chip
Function
RESET:
RESET:
Alt. Pin
DDB7
Bit 7
Bit 7
DBE
PE7
0
–
MODB or
Bits PB[7:0] are associated with addresses ADDR[7:0] and DATA[7:0].
When this port is not used for external addresses and data such as in
single-chip mode, these pins can be used as general-purpose I/O.
DDRB determines the primary direction of each pin. This register is not
in the on-chip map in expanded and peripheral modes. Read and write
anytime.
DDB6
This register determines the primary direction for each port B pin when
functioning as a general-purpose I/O port. DDRB is not in the on-chip
map in expanded and peripheral modes. Read and write anytime.
IPIPE1
This register is associated with external bus control signals and interrupt
inputs including data bus enable (DBE), mode select (MODB/IPIPE1,
MODA/IPIPE0), E clock, data size (LSTRB/TAGLO), read/write (R/W),
IRQ, and XIRQ. When the associated pin is not used for one of these
specific functions, the pin can be used as general-purpose I/O. The port
E assignment register (PEAR) selects the function of each pin. DDRE
determines the primary direction of each port E pin when configured to
be general-purpose I/O.
Some of these pins have software selectable pull-ups (DBE, LSTRB,
R/W, and XIRQ). A single control bit enables the pull-ups for all these
pins which are configured as inputs. IRQ always has a pull-up.
PE6
6
0
6
–
Freescale Semiconductor, Inc.
For More Information On This Product,
0 = Associated pin is a high-impedance input
1 = Associated pin is an output
MODA or
DDB5
IPIPE0
PE5
Bus Control and Input/Output
5
0
Go to: www.freescale.com
5
–
DDB4
ECLK
PE4
4
0
4
–
LSTRB or
TAGLO
DDB3
PE3
3
0
3
–
DDB2
PE2
R/W
2
0
2
–
DDB1
PE1
IRQ
1
0
1
–
DDB0
XIRQ
Bit 0
$0008
Bit 0
PE0
$0003
0
–
4-bus