MC68HC908LJ24 Datasheet, PDF (386/464 Pages) Motorola, Inc – Microcontrollers

Input/Output (I/O) Ports
Table 18-3 summarizes the operation of the port B pins.
Table 18-3. Port B Pin Functions
DDRB
Bit
0
PTB Bit
X⁽¹⁾
I/O Pin Mode
Input, Hi-Z⁽²⁾
Accesses to DDRB
Read/Write
DDRB[7:0]
1
X
Output
DDRB[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 PTB
Read
Pin
Write
PTB[7:0]⁽³⁾
PTB[7:0] PTB[7:0]
18.4.3 Port B LED Control Register (LEDB)
The port-B LED control register (LEDB) controls the direct LED drive
capability on PTB5–PTB0 pins. Each bit is individually configurable and
requires that the data direction register, DDRB, bit be configured as an
output.
When the IRSCI is enabled, setting the LEDB0 bit also enables high
current (15mA) sink capability for the TxD pin.
Address: $000C
Bit 7
6
5
4
3
2
1
Read: 0
Write:
0
LEDB5 LEDB4 LEDB3 LEDB2 LEDB1
Reset: 0
0
0
0
0
0
0
Figure 18-8. Port B LED Control Register (LEDB)
Bit 0
LEDB0
0
LEDB[5:0] — Port B 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 B pin is configured for direct LED drive,
with 15mA current sinking capability
0 = Corresponding port B pin is configured for standard drive
Data Sheet
386
Input/Output (I/O) Ports
MC68HC908LJ24/LK24 — Rev. 2.1
Freescale Semiconductor