MC68HC908LJ24 Datasheet, PDF (389/464 Pages) Motorola, Inc – Microcontrollers

Input/Output (I/O) Ports
Port C
When DDRCx is a logic 1, reading address $0002 reads the PTCx data
latch. When DDRCx is a logic 0, reading address $0002 reads the
voltage level on the pin. The data latch can always be written, regardless
of the state of its data direction bit.
Table 18-4 summarizes the operation of the port C pins.
Table 18-4. Port C Pin Functions
DDRC
Bit
0
PTC Bit
X⁽¹⁾
I/O Pin Mode
Input, Hi-Z⁽²⁾
Accesses to DDRC
Read/Write
DDRC[7:0]
1
X
Output
DDRC[7:0]
Notes:
1. X = don’t care.
2. Hi-Z = high impedance.
3. Writing affects data register, but does not affect input.
Accesses to PTC
Read
Pin
Write
PTC[7:0]⁽³⁾
PTC[7:0] PTC[7:0]
18.5.3 Port C LED Control Register (LEDC)
Port-C LED control register (LEDC) controls the direct LED drive
capability on PTC7–PTC0 pins. Each bit is individually configurable and
requires that the data direction register, DDRC, bit be configured as an
output.
Address: $000D
Bit 7
6
5
4
3
2
1
Read:
LEDC7
Write:
LEDC6
LEDC5
LEDC4
LEDC3
LEDC2
LEDC1
Reset: 0
0
0
0
0
0
0
Figure 18-12. Port C LED Control Register (LEDC)
Bit 0
LEDC0
0
LEDC[7:0] — Port C 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 C pin is configured for direct LED drive,
with 15mA current sinking capability
0 = Corresponding port C pin is configured for standard drive
MC68HC908LJ24/LK24 — Rev. 2.1
Freescale Semiconductor
Input/Output (I/O) Ports
Data Sheet
389