Microchip Technology IC PIC MCU PIC16F1937-I/PT TQFP-44 MCP PIC16F1937-I/PT Data Sheet

 2008-2011 Microchip Technology Inc.

DS41364E-page 359

The following is the sequence of steps to configure the
LCD module.
1.

Select the frame clock prescale using bits
LP<3:0> of the LCDPS register.

2.

Configure the appropriate pins to function as
segment drivers using the LCDSEn registers.

3.

Configure the LCD module for the following
using the LCDCON register:

- Multiplex and Bias mode, bits LMUX<1:0>

- Timing source, bits CS<1:0>
- Sleep mode, bit SLPEN

4.

Write initial values to pixel data registers,
LCDDATA0 through LCDDATA11.

5.

Clear LCD Interrupt Flag, LCDIF bit of the PIR2
register and if desired, enable the interrupt by
setting bit LCDIE of the PIE2 register.

6.

Configure bias voltages by setting the LCDRL, 
LCDREF and the associated ANSELx 
registers as needed.

7.

Enable the LCD module by setting bit LCDEN of
the LCDCON register.

To disable the LCD module, write all ‘0’s to the
LCDCON register.

When using the LCD module the current consumption
consists of the following three factors:
• Oscillator Selection
• LCD Bias Source
• Capacitance of the LCD segments
The current consumption of just the LCD module can
be considered negligible compared to these other
factors.

27.14.1

OSCILLATOR SELECTION

The current consumed by the clock source selected
must be considered when using the LCD module. See
the applicable Electrical Specifications Chapter for
oscillator current consumption information.

27.14.2

LCD BIAS SOURCE

The LCD bias source, internal or external, can contrib-
ute significantly to the current consumption. Use the
highest possible resistor values while maintaining
contrast to minimize current.

27.14.3

CAPACITANCE OF THE LCD 
SEGMENTS

The LCD segments which can be modeled as capaci-
tors which must be both charged and discharged every
frame. The size of the LCD segment and its technology
determines the segment’s capacitance.