
Page 48
Epson Research and Development
Vancouver Design Center
SED1352
Hardware Functional Specification
X16-SP-001-16
Issue Date: 99/07/28
bits 7-0
Line Byte Count Bits [7:0]
These are the 8 LSB of the 9 bit Total Display Line Count and represent the number of scan lines -1, to
a maximum value of 3FFh or 1024 scan lines. Line Byte Count Bit 8 is located in register AUX[05h] and
is ignored in the 16-bit memory interface. 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:
The following two tables summarize the maximum value of the Line Byte Count Register for different dis-
play modes and display memory interface.
bits 7-6
PS Bits [1:0]
Selects the Power Save Modes as shown in the following table. The PS bits [1:0] go low on RESET.
AUX[02h] 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
Table 8-1: Maximum Value of Line Byte Count Register - 8-Bit Display Memory Interface
Display Mode
Maximum Value of
Line Byte Count Register
Corresponding Maximum
Number of Pixels in One
Display Line
4-level gray shades
0FFh
256 x 4 = 1024
16-level gray shades
1FFh
512 x 2 = 1024
Table 8-2: Maximum Value of Line Byte Count Register - 16-Bit Display Memory Interface
Display Mode
Maximum Value of
Line Byte Count Register
Corresponding Maximum
Number of Pixels in One
Display Line
4-level gray shades
0FFh
256 x 8 = 2048
16-level gray shades
0FFh
256 x 4 = 1024
AUX[03h] Line Byte Count Power Save Register (MSB)
I/O address = 0011b, Read/Write
PS
Bit 1
PS
Bit 0
LCD Signal
State
LUT
Bypass
n/a
n/a
n/a
Line Byte
Count Bit 8
LineByteCount
BitsPerPixel
MemoryInterfaceWidth
--------------------------------------------------------------
HorizontalResolution
×
1
–
=
LineByteCount
4BitsPerPixel
16Bits
-------------------------------------
640
1
159
=
–
×
=