ade7169f16 Analog Devices, Inc., ade7169f16 Datasheet - Page 92

• Manufacturer Part Number: ade7169f16
• Description: Single-phase Energy Measurement Ic With 8052 Mcu, Rtc And Lcd Driver
• Manufacturer: Analog Devices, Inc.

ADE7169F16
Table 80. LCD Data SFR (LCDDAT, 0xAE)
Table 81. LCD Segment Enable 2 SFR (LCDSEGE2, 0xED)
LCD SETUP
The LCD Configuration SFR (LCDCON, 0x95) configures the
LCD module to drive the type of LCD in the user end system.
The BIAS and LMUX[1:0] bits in this SFR should be set
according to the LCD specifications.
The COM2/FP28 and COM3/FP27 pins default to LCD
segment lines. Selecting the 3x multiplex level in the LCD
Configuration SFR (LCDCON, 0x95) by setting LMUX[1:0] to
2d, changes the FP28 pin functionality to COM2. The 4x
multiplex level selection, LMUX[1:0]=3d, changes the FP28 pin
to COM2 and the FP27 pin to COM3.
LCD segments FP0-FP15 are enabled by default. Additional
pins are selected for LCD functionality in the LCD Segment
Enable SFR (LCDSEGE, 0x97) and LCD Segment Enable 2 SFR
(LCDSEGE2, 0xED) where there are individual enable bits for
segment pins FP16-25. The LCD pins do not have to be enabled
sequentially. For example, if the alternate function of FP23, the
timer 2 input, is required, then any of the other shared pins,
FP16-25, could be enabled instead.
The Display Element Control section contains details about
setting up the LCD data memory to turn individual LCD
segments ON and OFF. Setting the LCDRST bit in the LCD
Configuration SFR (LCDCON, 0x95) will reset the LCD data
memory to its default, zero. A power on reset also clears the
LCD data memory.
Bit
Location
7-0
Bit
Location
7-4
3
2
1
0
Bit
Mnemonic
LCDDATA
Bit
Mnemonic
RESERVED
FP19EN
FP18EN
FP17EN
FP16EN
0
Default
Value
Default
Value
0
0
0
0
0
Data to be written into or read out of the LCD Memory SFRs.
Description
Description
Reserved
FP19 Function Select bit
0
1
FP18 Function Select bit
0
1
FP17 Function Select bit
0
1
FP16 Function Select bit
0
1
Rev. PrD | Page 92 of 140
General Purpose I/O
LCD Function
General Purpose I/O
LCD Function
General Purpose I/O
LCD Function
General Purpose I/O
LCD Function
LCD TIMING AND WAVEFORMS
An LCD segment acts like a capacitor that is charged and
discharged at a certain rate. The rate at which these capacitors
are charged and discharged, the refresh rate, determines the
visual characteristics of the LCD. A slow refresh rate will result
in the user being able to see the LCD blink on and off in
between refreshes. A fast refresh rate will present a screen that
appears to be lit up continuously. However, a faster refresh rate
consumes more power.
The frame rate, or refresh rate, for the LCD module is derived
from the LCD clock, f
2048Hz or 128Hz by the CLKSEL bit in the LCD Configuration
X SFR (LCDCONX, 0x9C). The minimum refresh rate that is
needed for the LCD to appear solid, without blinking, is
independent of the multiplex level.
The LCD waveform frequency, f
the LCD switches which common line is active. Thus the LCD
waveform frequency depends heavily on the multiplex level.
The frame rate and LCD waveform frequency are set by f
the multiplex level and the FD[3:0] frame rate selection bits in
the LCD Clock SFR (LCDCLK, 0x96).
The LCD module provides 16 different frame rates for
f
multiplexing. There are fewer options available with
f
LCDCLK
LCDCLK
=2048Hz, ranging from 8 to 128Hz for an LCD with 4x
=128Hz, ranging from 8 to 32Hz for a 4x multiplexed
LCDCLK
Preliminary Technical Data
. The LCD clock is selected as
LCD
, is the frequency at which
LCDCLK
,