Epson Research and Development
Page 63
Vancouver Design Center
Hardware Functional Specification
S1D13503
Issue Date: 01/01/29
X18A-A-001-08
bit 2
LCD Data Width Bit 0
Together with LCD Data Width bit 1 (AUX[03] bit 3) this bit selects different display data formats. The
following table shows the function of these two bits:
For 8-bit dual panels, the data transfer width is forced to 4 bits per panel. This bit goes low on RESET.
bit 1
Memory Interface
This bit selects between the 8-bit or 16-bit memory interface. When this bit = 0, the 16-bit memory inter-
face is selected. When this bit = 1, the 8-bit memory interface is selected. If 16-bit bus interface (VD0 = 1
on RESET) or 256 color mode (AUX[03] bits 2-1 = 11) is selected, the Memory Interface bit is forced to 0
internally (16-bit). This bit goes low on RESET.
bit 0
RAMS
This bit configures the display memory address lines for an 8-bit memory interface system. When this bit
= 0, addressing for 8Kx8 SRAM on an 8-bit display memory data bus interface is selected. When this bit =
1, addressing for 32Kx8 SRAM on an 8-bit display memory data bus interface is selected. This bit goes
low on RESET. This bit is ignored for a 16-bit memory interface.
bits 7-0
Line Byte Count Bits [7:0]
Along with Line Byte Count Bit 8 (AUX[03] bit 0), this is the number of bytes to be fetched per display
line minus 1. To calculate the Line Byte Count use the following formula:
Example:
To calculate the Line Byte Count for 640 horizontal pixels with 16 gray shades (4 bits-per-pixel) and 16-bit
memory interface:
Table 8-2: LCD Data Width
Panel
LCD Data
Width Bit 1
AUX[03] bit 3
LCD Data
Width Bit 0
AUX[01] bit 2
Function
Monochrome
don’t care
0
4-bit LCD data width
Monochrome
don’t care
1
8-bit LCD data width
Color
0
0
4-bit LCD data width
Color
0
1
8-bit LCD data width - format 1
Color
1
0
16-bit LCD data width (with external circuit)
Color
1
1
8-bit LCD data width - format 2
AUX[02] Line Byte Count Register (LSB)
I/O address = 0010b, Read/Write.
Line Byte
Count Bit 7
Line Byte
Count Bit 6
Line Byte
Count Bit 5
Line Byte
Count Bit 4
Line Byte
Count Bit 3
Line Byte
Count Bit 2
Line Byte
Count Bit 1
Line Byte
Count Bit 0
LineByteCount Decimal
(
)
BitsPerPixel
MemoryInterfaceWidth
--------------------------------------------------------------
HorizontalResolution
×
1
–
=
LineByteCount Decimal
(
)
4BitsPerPixel
16Bits
-------------------------------------
640
1
159
=
–
×
=
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