STE2002 Datasheet, PDF (9/51 Pages) STMicroelectronics – 81 X 128 SINGLE CHIP LCD CONTROLLER / DRIVER

STE2002
Display Data RAM
The STE2002, provides an 104X128 bits Static RAM to store Display data. This is organized into 13
(Bank0 to Bank12) banks with 128 Bytes. One of these banks (128 bits wide) can be used for Icons. RAM
access is accomplished in either one of the Bus Interfaces provided (see below). Allowed addresses are
X0 to X127 (Horizontal) and Y0 to Y12 (Vertical).
When writing to RAM, four addressing mode are provided:
• Normal Horizontal (MX=0 and V=0), having the column with address X= 0 located on the left of the mem-
ory map. The X pointer is increased after each byte written. After the last column address (X=X-Car-
riage), Y address pointer is set to jump to the following bank and X restarts from X=0. (Fig. 6)
• Normal Vertical (MX=0 and V=1), having the column with address X= 0 located on the left of the memory
map. The Y pointer is increased after each byte written. After the last Y bank address (Y=Y-Carriage),
X address pointer is set to jump to next column and Y restarts from Y=0 (Fig. 7).
• Mirrored Horizontal (MX=1 and V=0), having the column with address X= 0 located on the right of the
memory map. The X pointer is increased after each byte written. After the last column address (X=X-
Carriage), Y address pointer is set to jump to the next bank and X restarts from X=0 (fig. 8).
• Mirrored Vertical (MX=1 and V=1), having the column with address X= 0 located on the right of the mem-
ory map. The Y pointer is increased after each byte written. After the last Y bank address (Y=Y-Car-
riage), the X pointer is set to jump to next column and Y restarts from Y=0 (fig. 9).
After the last allowed address (X;Y)=(X-Carriage; Y-Carriage), the address pointers always jump to the
cell with address (X;Y) = (0;0) (Fi. 10, 11, 12 & 13).
Data bytes in the memory could have the MSB either on top (D0 = 0, Fig.14) or on the bottom (D0=1, Fig.
15).
The STE2002 provides also means to alter the normal output addressing. A mirroring of the Display along
the X axis is enabled setting to a logic one MY bit.This function doesn't affect the content of the memory
RAM. It is only related to the visualization process.
When ICON MODE=1 the Icon Row is not mirrored with MY and is not scrolled. When ICON Mode=0 the
Icon Row is like the other graphic lines and is mirrored and scrolled.
Four are the multiplex ratio available when the partial display mode is disabled (MUX 33, MUX 49, MUX
65 and MUX 81).
Only a subset of writable rows are output on Row drivers.
When Y-Carriage<MUX/8, if Mux 65 is selected only the first 65 memory rows are visualized, if Mux 49 is
selected only the first 49 memory rows are visualized, if Mux 33 is selected only the first 33 memory rows
are visualized. All unused Row and Column drivers must be left floating.
When Y-Carriage<MUX/8, the icon Bank is located to BANK 10 in MUX 81 Mode, to BANK8 in MUX 65
Mode, to BANK 6 in MUX 49 Mode and to BANK 4 in MUX 33 Mode.
When Y-Carriage>MUX/8 lines only 33, 49, 65 or 81 lines are visualized but it is possible to select which
lines of DDRAM are connected on the output drivers. The DDRAM rows to visualized can be selected in
the 0-Y-Carriage*8 range using the scrolling function.
When Y-Carriage>MUX lines, the icon row is moved in DDRAM to the first row of the Y-CARRIAGE Re-
turn BANK even if it is always connected on the same output Driver.
When MY=0, the icon Row is output on R80 in mux 81 mode, on R72 in MUX 65, on R64 in MUX49 and
on R56 in MUX 33.
When MY=1, and ICON MODE=1, the icon Row is output on R80 in mux 81 mode, on R72 in MUX 65, on
R64 in MUX49 and on R56 in MUX 33.
When MY=1, and ICON MODE=0, the icon Row is output on R0 whatever is the MUX Rate.
When ICON MODE =1, the Memory ICON Row content is output on ICON Pad.
If Not Used ICON Pad must be left floating.
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