s908qy2ad1vdwer Freescale Semiconductor, Inc, s908qy2ad1vdwer Datasheet - Page 104

• Manufacturer Part Number: s908qy2ad1vdwer
• Description: Mc68hc908qt4a Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

Input/Output Ports (PORTS)
12.3.1 Port A Data Register
The port A data register (PTA) contains a data latch for each of the six port A pins.
PTA[5:0] — Port A Data Bits
AWUL — Auto Wakeup Latch Data Bit
12.3.2 Data Direction Register A
Data direction register A (DDRA) determines whether each port A pin is an input or an output. Writing a 1
to a DDRA bit enables the output buffer for the corresponding port A pin; a 0 disables the output buffer.
DDRA[5:0] — Data Direction Register A Bits
Figure 12-3
104
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.
This is a read-only bit which has the value of the auto wakeup interrupt request latch. The wakeup
request signal is generated internally (see
port nor any of the associated bits such as PTA6 data register, pullup enable or direction.
These read/write bits control port A data direction. Reset clears DDRA[5:0], configuring all port A pins
as inputs.
1 = Corresponding port A pin configured as output
0 = Corresponding port A pin configured as input
shows the port A I/O logic.
Reset:
Reset:
Read:
Write:
Read:
Write:
Avoid glitches on port A pins by writing to the port A data register before
changing data direction register A bits from 0 to 1.
Bit 7
Bit 7
R
R
R
0
Figure 12-2. Data Direction Register A (DDRA)
= Unimplemented
= Reserved
AWUL
Figure 12-1. Port A Data Register (PTA)
MC68HC908QYA/QTA Family Data Sheet, Rev. 2
R
6
6
0
DDRA5
PTA5
5
5
0
Chapter 4 Auto Wakeup Module
DDRA4
Unaffected by reset
PTA4
NOTE
4
4
0
= Unimplemented
DDRA3
PTA3
3
3
0
PTA2
2
2
0
0
DDRA1
PTA1
1
1
0
(AWU)). There is no PTA6
Freescale Semiconductor
DDRA0
PTA0
Bit 0
Bit 0
0