
Data Sheet
MC68HC08AS32 — Rev. 4.1
150
Freescale Semiconductor
whether reading port E returns the states of the latches or the states of the pins.
TCH[1:0] — Timer Channel I/O Bits
The PTE3/TCH1–PTE2/TCH0 pins are the TIM input capture/output compare
pins. The edge/level select bits, ELSxB:ELSxA, determine whether the
PTE3/TCH1–PTE2/TCH0 pins are timer channel I/O pins or general-purpose
NOTE:
Data direction register E (DDRE) does not affect the data direction of port E
pins that are being used by the TIM. However, the DDRE bits always determine
whether reading port E returns the states of the latches or the states of the pins.
RxD — SCI Receive Data Input Bit
The PTE1/RxD pin is the receive data input for the SCI module. When the
enable SCI bit, ENSCI, is clear, the SCI module is disabled, and the PTE1/RxD
TxD — SCI Transmit Data Output
The PTE0/TxD pin is the transmit data output for the SCI module. When the
enable SCI bit, ENSCI, is clear, the SCI module is disabled, and the PTE0/TxD
NOTE:
Data direction register E (DDRE) does not affect the data direction of port E pins
that are being used by the SCI module. However, the DDRE bits always determine
whether reading port E returns the states of the latches or the states of the pins.
11.6.2 Data Direction Register E
Data direction register E 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.
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
Address:
$000C
Bit 7
6
54321
Bit 0
Read:
DDRE7
DDRE6
DDRE5
DDRE4
DDRE3
DDRE2
DDRE1
DDRE0
Write:
Reset:
00
000000
Figure 11-15. Data Direction Register E (DDRE)