s908ey16g2vfar Freescale Semiconductor, Inc, s908ey16g2vfar Datasheet - Page 130

• Manufacturer Part Number: s908ey16g2vfar
• Description: M68hc08 Microcontrollers Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

Input/Output (I/O) Ports (PORTS)
12.6 Port E
Port E is a 2-bit special function port that shares its pins with the enhanced serial communications
interface module (ESCI).
12.6.1 Port E Data Register
The port E data register contains a data latch for each of the port E pins.
PTE[1:0] — Port E Data Bits
12.6.2 Data Direction Register E
Data direction register E determines whether each port E pin is an input or an output. Writing a 1 to a
DDRE bit enables the output buffer for the corresponding port E pin; a 0 disables the output buffer.
DDRE[1:0] — Data Direction Register E Bits
Figure 12-15
130
These read/write bits are software programmable. Data direction of each port E pin is under the control
of the corresponding bit in data direction register E. Reset has no effect on PTE[1:0].
These read/write bits control port E data direction. Reset clears DDRE[1:0], configuring all port E pins
as inputs.
1 = Corresponding port E pin configured as output
0 = Corresponding port E pin configured as input
Alternative Function:
Address:
shows the port E I/O logic.
Avoid glitches on port E pins by writing to the port E data register before
changing data direction register E bits from 0 to 1.
Reset:
Read:
Write:
Address:
Reset:
Read:
Write:
$000A
Bit 7
0
0
$0008
Figure 12-14. Data Direction Register E (DDRE)
MC68HC908EY16A • MC68HC908EY8A Data Sheet, Rev. 1
Bit 7
0
= Unimplemented
Figure 12-13. Port E Data Register (PTE)
6
0
0
= Unimplemented
6
0
5
0
0
5
0
NOTE
4
0
0
Unaffected by reset
4
0
3
0
0
3
0
2
0
0
2
0
DDRE1
1
0
PTE1
RxD
1
Freescale Semiconductor
DDRE0
Bit 0
0
PTE0
Bit 0
TxD