MC68HC908LJ24 Datasheet, PDF (396/464 Pages) Motorola, Inc – Microcontrollers

Input/Output (I/O) Ports
When DDREx is a logic 1, reading address $0008 reads the PTEx data
latch. When DDREx is a logic 0, reading address $0008 reads the
voltage level on the pin. The data latch can always be written, regardless
of the state of its data direction bit.
Table 18-6 summarizes the operation of the port E pins.
Table 18-6. Port E Pin Functions
DDRE
Bit
0
PTE Bit
X⁽¹⁾
I/O Pin Mode
Input, Hi-Z⁽²⁾
Accesses to DDRE
Read/Write
DDRE[7:0]
1
X
Output
DDRE[7:0]
Notes:
1. X = don’t care; except.
2. Hi-Z = high impedance.
3. Writing affects data register, but does not affect input.
Accesses to PTE
Read
Pin
Write
PTE[7:0]⁽³⁾
PTE[7:0] PTE[7:0]
18.7.3 Port E LED Control Register (LEDE)
The port-E LED control register (LEDE) controls the direct LED drive
capability on PTE7–PTE0 pins. Each bit is individually configurable and
requires that the data direction register, DDRE, bit be configured as an
output.
Address: $000E
Bit 7
6
5
4
3
2
1
Read:
LEDE7
Write:
LEDE6
LEDE5
LEDE4
LEDE3
LEDE2
LEDE1
Reset: 0
0
0
0
0
0
0
Figure 18-19. Port E LED Control Register (LEDE)
Bit 0
LEDE0
0
LEDE[7:0] — Port E LED Drive Enable Bits
These read/write bits are software programmable to enable the direct
LED drive on an output port pin.
1 = Corresponding port E pin is configured for direct LED drive,
with 15mA current sinking capability
0 = Corresponding port E pin is configured for standard drive
Data Sheet
396
Input/Output (I/O) Ports
MC68HC908LJ24/LK24 — Rev. 2.1
Freescale Semiconductor