mc68hc908sr12 Freescale Semiconductor, Inc, mc68hc908sr12 Datasheet - Page 320

• Manufacturer Part Number: mc68hc908sr12
• Description: M68hc08 Microcontrollers Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

Input/Output (I/O) Ports
18.3 Port A
18.3.1 Port A Data Register (PTA)
Data Sheet
320
Alternative Function:
Additional Function:
Address:
Port A is an 8-bit special function port that shares six of its port pins with
the analog-to-digital converter (ADC) module and two of its port pins with
the timer interface module 1 (TIM1). See
Converter (ADC)
PTA5–PTA0 pins can be configured for direct LED drive.
The port A data register contains a data latch for each of the eight port A
pins.
PTA[7:0] — Port A Data Bits
ATD[7:2] — ADC channels 2 to 7
Reset:
Read:
Write:
These read/write bits are software programmable. Data direction of
each port A pin is under the control of the corresponding bit in data
direction register A. Reset has no effect on port A data.
ATD[7:2] are pins used for the input channels to the analog-to-digital
converter module. The channel select bits, ADCH[4:0], in the ADC
status and control register define which port pin will be used as an
ADC input and overrides any control from the port I/O logic. See
Section 14. Analog
T1CH1
$0000
PTA7
Bit 7
Figure 18-2. Port A Data Register (PTA)
Input/Output (I/O) Ports
T1CH0
PTA6
6
and
Section 11. Timer Interface Module
LED drive LED drive LED drive LED drive LED drive LED drive
Module.
PTA5
ATD7
5
MC68HC908SR12•MC68HC08SR12 — Rev. 5.0
Unaffected by Reset
PTA4
ATD6
4
Section 15. Analog-to-Digital
PTA3
ATD5
3
PTA2
ATD4
Freescale Semiconductor
2
PTA1
ATD3
1
(TIM).
PTA0
ATD2
Bit 0