PCF8811U/2DA/1 NXP [NXP Semiconductors], PCF8811U/2DA/1 Datasheet - Page 28

• Manufacturer Part Number: PCF8811U/2DA/1
• Description: 80 x 128 pixels matrix LCD driver
• Manufacturer: NXP [NXP Semiconductors]

NXP Semiconductors
PCF8811_4
Product data sheet
Fig 19. Read mode SPI 3-line and 4-line
SDATA
SCLK
SDO
SCE
RES
10.1.2 Read mode (only extended command set)
10.2.1 Write mode
10.2 Serial interface (3-line)
DB7 DB6 DB5 DB4
The read mode of the interface means that the microcontroller reads data from the
PCF8811. To do so, the microcontroller first has to send a command (the read status
command) and then the PCF8811 will respond by transmitting data on the SDO line. After
that, SCE is required to go HIGH; see
The PCF8811 samples the SDATA data on rising SCLK edges, but shifts SDO data on
falling SCLK edges. So, the microcontroller is supposed to read SDO data on rising SCLK
edges.
After the read status command has been sent, the SDATA line must be set to 3-state not
later then the falling SCLK edge of the last bit; see
Serial interface timing diagrams are shown in
The serial interface is also a 3-line bidirectional interface for communication between the
microcontroller and the LCD driver chip. The 3 lines are:
The PCF8811 is connected to the SDA of the microcontroller by two lines: SDATA (data
input) and SDO (data output) which are connected together.
The write mode of the interface means that the microcontroller writes commands and data
to the PCF8811. Each data packet contains a control bit (D/C) and a transmission byte. If
D/C is LOW, the following byte is interpreted as a command byte. The instruction set is
shown in
After every data byte the address counter is incremented automatically.
the general format of the write mode and the definition of the transmission byte.
•
•
•
SCE (chip enable)
SCLK (serial clock)
SDATA (serial data)
Table
instruction
10. If D/C is HIGH, the following byte is stored in the display data RAM.
DB3
DB2
Rev. 04 — 27 June 2008
DB1 DB0
DB7 DB6 DB5 DB4 DB3
Figure
19.
Section
read out data
Figure
16.2.
80 x 128 pixels matrix LCD driver
DB2
19.
DB1 DB0
PCF8811
© NXP B.V. 2008. All rights reserved.
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