Datasheet

Liquid Crystal Display (LCD) Driver
Data Sheet MC68HC908LJ24/LK24 — Rev. 2.1
350 Liquid Crystal Display (LCD) Driver Freescale Semiconductor
17.2 Introduction
This section describes the liquid crystal display (LCD) driver module.
The LCD driver module can drive a maximum of 33 frontplanes and 4
backplanes, depending on the LCD duty selected.
17.3 Features
Features of the LCD driver module include the following:
• Software programmable driver segment configurations:
– 32 frontplanes × 4 backplanes (128 segments)
– 33 frontplanes × 3 backplanes (99 segments)
– 33 frontplanes × 1 backplane (33 segments)
• LCD bias voltages generated by internal resistor ladder
• Software programmable contrast control
17.4 Pin Name Conventions and I/O Register Addresses
Three dedicated I/O pins are for the backplanes, BP0–BP2; sixteen
dedicated I/O pins are for the frontplanes, FP1–FP10 and FP27–FP32;
and the sixteen frontplanes, FP11–FP26, are shared with port C and E
pins. FP0 and BP3 shares the same pin and configured by the
DUTY[1:0] bits in the LCD clock register.
The full names of the LCD output pins are shown in Table 17-1. The
generic pin names appear in the text that follows.
Table 17-1. Pin Name Conventions
LCD Generic Pin Name Full MCU Pin Name Pin Selected for LCD Function by:
FP0/BP3 FP0/BP3 —
BP0–BP2 BP0–BP2 —
FP1–FP10 FP1–FP10 —
FP11–FP18 PTE0/FP11–PTE7/FP18 PEE in CONFIG2
FP19–FP26 PTC0/FP19–PTC7/FP26 PCEL:PCEH in CONFIG2
FP27–FP32 FP27–FP32 —