PCF8820U Philips Semiconductors, PCF8820U Datasheet - Page 19

• Manufacturer Part Number: PCF8820U
• Description: 67 x 101 Grey-scale/ECB colour dot matrix LCD driver
• Manufacturer: Philips Semiconductors

Philips Semiconductors
8
The PCF8820 interfaces via the I
LCD is not required to process instructions.
The data received by the PCF8820 is either instruction
data which defines its operating mode or display data to be
stored in its DDRAM. The type of data is identified by
bit RS. When bit RS = 0, the PCF8820 will respond to the
instructions. When bit RS = 1, the PCF8820 will load the
data into its DDRAM.
There are four types of instruction data whose functions
are listed below:
Table 2 Instruction set
2000 Dec 07
Independent command page (H
Write data
Read
temperature
NOP
Default H
Function and RAM command page (H
Instruction set
Select function
Set Y address of
DDRAM
Set X address of
DDRAM
Display setting command page (H
Display control
External display
control
Bias system
Bias system
INSTRUCTION
Define PCF8820 functions, such as display
configuration, etc.
Set DDRAM addresses
Perform data transfers to DDRAM
Other functions.
67 101 Grey-scale/ECB colour dot matrix
LCD driver
INSTRUCTIONS
2
to H
1
/
2
0
CONTROL
RS
1
0
0
0
0
0
0
0
0
0
0
0
BITS
R/W DB7 DB6 DB5 DB4 DB3 DB2 DB1
(1)
0
1
0
0
0
0
0
0
0
0
0
0
2
TR
C-bus. The clock of the
D
2
0
0
0
0
0
1
0
0
0
0
7
= X, H
7
2
= 0, H
TR
2
D
X
0
0
0
0
1
0
0
0
0
1
= 0, H
6
6
6
= X, H
1
= 0, H
TR
D
X
0
0
0
0
0
0
0
0
1
1
5
5
5
0
= 0, H
COMMAND BYTE
= X); note 2
0
TR
= 1)
D
Y
X
0
0
0
1
0
0
1
1
4
4
4
0
4
= 0)
19
TR
In normal use, the most frequently used instructions are
those which perform data transfers to the DDRAM.
Address pointer update follows after the data byte has
been written to the DRAM. This reduces the program load
of the microcontroller.
Undefined register locations are not allowed.
The instruction set comprises several command pages.
A command page is selected by setting bits H
The instruction set is given in Table 2.
The bit functions are described in detail in Section 8.1.
DO
D
Y
X
0
0
1
0
1
0
1
3
3
3
3
TR
BS
MX
PD
D
H
Y
X
0
0
1
0
2
2
2
2
2
2
TR
BS
MY
D
H
Y
X
D
V
0
0
0
1
1
1
1
1
1
BS
DB0
TR
BS
PS
D
H
Y
X
E
0
1
0
0
0
0
0
1
0
0
/
2
writes data to DDRAM
reads sensor temperature
read-out
no operation
jumps to function and RAM
command page
selects a command page
data order; power-down
control; address mode
selects Y-address of
DDRAM: 0
selects X-address of
DDRAM: 0
selects display mode
mirror X; mirror Y; partial
screen mode
selects bias system
set bias system
screen mode
DESCRIPTION
Product specification
PCF8820
Y
X
1
/
16
100
2
0
for partial
to H
2
.