lpc12d27 NXP Semiconductors, lpc12d27 Datasheet - Page 15

• Manufacturer Part Number: lpc12d27
• Description: 32-bit Arm Cortex-m0 Microcontroller; 128 Kb Flash And 8 Kb Sram; 40 Segment X 4 Lcd Driver
• Manufacturer: NXP Semiconductors

NXP Semiconductors
LPC12D27
Product data sheet
7.2.5.1 Internal clock
7.2.2 Functional description
7.2.3 Reset state of the LCD controller and pins
7.2.4 LCD bias generator
7.2.5 Oscillator
The PCF8576D is a versatile peripheral device interfacing the LPC1227 microcontroller
with a wide variety of LCDs. It can directly drive any static or multiplexed LCD containing
up to four backplanes and up to 40 segments.
The possible display configurations of the PCF8576D depend on the number of active
backplane outputs required. A selection of display configurations is shown in
integration of the LPC1227 microcontroller with the PCF8576D is shown in
Table 4.
After power-on, the LCD controller resets to the following starting conditions:
Remark: Do not transfer data on the
reset action to complete.
Fractional LCD biasing voltages are obtained from an internal voltage divider consisting of
three impedances connected in series between V
can be bypassed to provide a 1/2 bias voltage level for the 1:2 multiplex configuration. The
LCD voltage can be temperature compensated externally using the supply to pin V
The internal logic of the PCF8576D and its LCD drive signals are timed either by its
internal oscillator or by an external clock. The internal oscillator is enabled by connecting
pin OSC to pin V
used as the clock signal for several PCF8576Ds in the system that are connected in
cascade.
Number of
Backplanes
4
3
2
1
•
•
•
•
•
•
•
All backplane and segment outputs are set to V
The selected drive mode is 1:4 multiplex with 1/3 bias.
Blinking is switched off.
Input and output bank selectors are reset.
The I
The data pointer and the subaddress counter are cleared (set to logic 0).
The display is disabled.
2
C-bus interface is initialized.
Selection of display configurations
All information provided in this document is subject to legal disclaimers.
Segments
160
120
80
40
SS(LCD)
Rev. 1 — 20 September 2011
. If the internal oscillator is used, the output from pin CLK can be
Digits/Characters
7-segment
20
15
10
5
I
2
C
-bus for at least 1 ms after a power-on to allow the
32-bit ARM Cortex-M0 microcontroller
14-segment
10
7
5
2
LCD
LCD
and V
.
SS(LCD)
Dot matrix/Elements
160 (4  40)
120 (3  40)
64 (2  40)
40 (1  40)
. The middle resistor
LPC12D27
© NXP B.V. 2011. All rights reserved.
Figure
Table
1.
4. The
LCD
15 of 46
.