ST7533 Sitronix Technology, ST7533 Datasheet - Page 15

• Manufacturer Part Number: ST7533
• Description: 33 x 96 Dot Matrix LCD Controller/Driver
• Manufacturer: Sitronix Technology

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ST7533
Display Data RAM
The display data RAM stores the dot data for the LCD. It has
a 33 (4 page x 8 bit +1) x 96 bit structure.
as is shown in Figure 3, the D7 to D0 display data from the
MPU corresponds to the LCD display common direction,
there are few constraints at the time of display data transfer
when multiple ST7533 are used, thus and display structures
can be created easily and with a high degree of freedom.
The Page Address Circuit
Page address of the display data RAM is specified through
the Page Address Set Command. The page address must be
specified again when changing pages to perform access.
The Column Addresses
The display data RAM column address is specified by the
Column Address Set command. The specified column
address is incremented (+1) with each display data
read/write command. This allows the MPU display data to be
accessed continuously. Moreover, the incrementing of
column addresses stops with 5FH. Because the column
address is independent of the page address, when moving,
for example, from page 0 column 5FH to page 1 column 00H,
The Line Address Circuit
The line address circuit, as shown in Table 4, specifies the
line address relating to the COM output when the contents of
the display data RAM are displayed. Using the display start
line address set command, what is normally the top line of
the display can be specified (this is the COM0 output when
the common output mode is normal, and the COM31 output
Ver 1.0
D0
D1
D2
D3
D4
-
0
1
0
0
1
1
0
0
1
0
Display data RAM
1
0
0
1
0
SEG Output
(D0) “0”
(D0) “1”
1
0
0
1
0
ADC
0
0
0
0
0
5F(H)
SEG0
0 (H)
Figure 3
← Column Address ←
Table 4
→ Column Address →
15/60
Moreover, reading from and writing to the display RAM from
the MPU side is performed through the I/O buffer, which is an
independent operation from signal reading for the liquid
crystal driver. Consequently, even if the display data RAM is
accessed asynchronously during liquid crystal display, it will
not cause adverse effects on the display (such as flickering).
Page address 8 (D3, D2, D1, D0 = 1, 0, 0, 0) is a special
RAM for icons, and only display data D0 is used.
it is necessary to respecify both the page address and the
column address.
Furthermore, as is shown in Table 4, the ADC command
(segment driver direction select command) can be used to
reverse the relationship between the display data RAM
column address and the segment output. Because of this,
the constraints on the IC layout when the LCD module is
assembled can be minimized. As is shown in Figure 4,
for ST7533 , the detail is shown page.11 The display area is
a 33 line area for the ST7533.
If the line addresses are changed dynamically using the
display start line address set command, screen scrolling,
page swapping, etc. can be performed.
(see Figure 4)
COM0
COM1
COM2
COM3
COM4
-
SEG 95
5F(H)
0 (H)
Liquid crystal display
2003/07/21