MC68HC05L28B MOTOROLA [Motorola, Inc], MC68HC05L28B Datasheet - Page 31

• Manufacturer Part Number: MC68HC05L28B
• Description: Flexible general-purpose microcomputer
• Manufacturer: MOTOROLA [Motorola, Inc]

2.2.7
These 16 I/O lines comprise ports A and B. The state of any pin is software programmable, and all
the pins are configured as inputs during power-on or reset. Port B pins in output mode can sink
10mA of current to drive the LEDs.
2.2.8
These six I/O lines comprise port D. The state of any pin is software programmable, and all the
pins are configured as inputs during power-on or reset. This port shares its pins with the 16-bit
timer and I
the different functions. All the port bits can be configured as input/output pins or used by other
systems within the MCU.
This 6-bit I/O port shares its pins with other subsystems on the MCU and is controlled using the
port D control (COND) and select (SELD) registers. On reset, all registers except the data register
are cleared thereby configuring all port pins as normal inputs with pull-up resistors. Writing a ‘1’ to
any bit in COND connects the subsystem function to the corresponding port D pin.
2.2.9
These signals comprise the LCD driver subsystem. The subsystem has a maximum of 18
frontplanes and four backplanes.
2.2.10 AD0 – AD1, VREFH/VREFL
These 4 signals comprise the A-to-D interface. The subsystem has a maximum of two A/D
channels.
MC68HC05L28
PA0 – PA7, PB0 – PB7
PD0 – PD5
BP0 – BP3, FP0 – FP17
2
C subsystems. There are four read/write registers associated with the port to select
MODES OF OPERATION AND PIN DESCRIPTIONS
MOTOROLA
TPG
2-9
2