MC68HC08AZ60ACFU MOTOROLA [Motorola, Inc], MC68HC08AZ60ACFU Datasheet - Page 320

• Manufacturer Part Number: MC68HC08AZ60ACFU
• Description: Microcontrollers
• Manufacturer: MOTOROLA [Motorola, Inc]

I/O Ports
20.4 Port B
20.4.1 Port B Data Register (PTB)
Advance Information
320
NOTE:
$0001
ALTERNATE
FUNCTIONS
PTB
Reset:
Read:
Write:
Port B is an 8-bit special function port that shares all of its pins with the
analog to digital convertor.
The port B data register contains a data latch for each of the eight port
B pins.
PTB[7:0] — Port B Data Bits
ATD[7:0] — ADC Channels
PTB7/ATD7– PTB0/ATD0 are eight of the analog to digital converter
channels. The ADC channel select bits, CH[4:0], determine whether the
PTB7/ATD7–PTB0/ATD0 pins are ADC channels or general-purpose
I/O pins. If an ADC channel is selected and a read of this corresponding
bit in the port B data register occurs, the data will be zero if the data
direction for this bit is programmed as an input. Otherwise, the data will
reflect the value in the data latch. Data direction register B (DDRB) does
not affect the data direction of port B pins that are being used by the
ADC. However, the DDRB bits always determine whether reading port B
returns the states of the latches or logic 0.
These read/write bits are software programmable. Data direction of
each port B pin is under the control of the corresponding bit in data
direction register B. Reset has no effect on port B data.
PTB7
ATD7
Bit 7
Figure 20-4. Port B Data Register (PTB)
PTB6
ATD6
6
I/O Ports
PTB5
ATD5
5
Unaffected by reset
PTB4
ATD4
4
PTB3
ATD3
3
MC68HC08AZ60A — Rev 0.0
PTB2
ATD2
2
PTB1
ATD1
1
MOTOROLA
PTB0
ATD0
Bit 0