Input/Output (I/O) Ports (PORTS)
10.6 Port E
Port E is an 8-bit, special function port that shares five of its pins with the timer
interface module (TIM) and two of its pins with the serial communications interface
module (SCI).
10.6.1 Port E Data Register
The port E data register (PTE) contains a data latch for each of the eight port E
pins.
Address:
$0008
Bit 7
6
5
4
3
2
1
Bit 0
Read:
Write:
Reset:
PTE7
PTE6
PTE5
PTE4
PTE3
PTE2
PTE1
PTE0
Unaffected by reset
Figure 10-13. Port E Data Register (PTE)
PTE[7:0] — Port E Data Bits
PTE[7:0] are read/write, software-programmable bits. Data direction of each
port E pin is under the control of the corresponding bit in data direction
register E.
NOTE:
Data direction register E (DDRE) does not affect the data direction of port E pins
that are being used by the TIMA or TIMB. However, the DDRE bits always
determine whether reading port E returns the states of the latches or the states of
the pins.
10.6.2 Data Direction Register E
Data direction register E (DDRE) determines whether each port E pin is an input or
an output. Writing a logic 1 to a DDRE bit enables the output buffer for the
corresponding port E pin; a logic 0 disables the output buffer.
Address:
$000C
Bit 7
6
DDRE6
0
5
DDRE5
0
4
DDRE4
0
3
DDRE3
0
2
DDRE2
0
1
DDRE1
0
Bit 0
DDRE0
0
Read:
Write:
Reset:
DDRE7
0
Figure 10-14. Data Direction Register E (DDRE)
DDRE[7:0] — Data Direction Register E Bits
These read/write bits control port E data direction. Reset clears DDRE[7:0],
configuring all port E pins as inputs.
1 = Corresponding port E pin configured as output
0 = Corresponding port E pin configured as input
Data Sheet
120
MC68HC908MR32 • MC68HC908MR16 — Rev. 6.0
Input/Output (I/O) Ports (PORTS)
MOTOROLA
FREESCALE [ Freescale ]
