MC912DG128A Motorola, MC912DG128A Datasheet - Page 262

• Manufacturer Part Number: MC912DG128A
• Description: Microcontrollers
• Manufacturer: Motorola

IBPURD — Pull-Up and Reduced Drive for Port IB
PORTIB — Port Data IB Register
Inter-IC Bus
MC68HC912DT128A Rev 2.0
262
RESET:
RESET:
IIC
Bit 7
PIB7
Bit 7
SCL
0
0
-
Read and write anytime
RDPIB - Reduced Drive of Port IB
PUPIB - Pull-Up Port IB Enable
Read and write anytime.
IIC functions SCL and SDA share port IB pins 7 and 6 and take
precedence over the general-purpose port when IIC is enabled. The
SCL and SDA output buffers behave as open-drain outputs.
When port is configured as input, a read will return the pin level. Port bits
5 through 0 have internal pull ups when configured as inputs so they will
read ones.
When configured as output, a read will return the latched output data.
Port bits 5 through 0 will read the last value written. A write will drive
associated pins only if configured for output and IIC is not enabled.
Port bits 5 through 0 do not have available external pins for
MC68HC912DT128A.
PIB6
SDA
6
0
0
6
-
0 = All port IB output pins have full drive enabled.
1 = All port IB output pins have reduced drive capability.
0 = Port IB pull-ups are disabled.
1 = Enable pull-up devices for port IB input pins [7:6]. Pull-ups for
port IB input pins [5:0] are always enabled.
PIB5
5
0
0
5
-
-
RDPIB
Inter-IC Bus
PIB4
4
0
4
-
-
PIB3
3
0
0
3
-
-
PIB2
2
0
0
2
-
-
PIB1
1
1
0
0
-
-
PUPIB
PIB0
Bit 0
Bit 0
0
-
-
MOTOROLA
$00E5
16-iicbus
$00E6