Page 64
Epson Research and Development
Vancouver Design Center
S1D13503
Hardware Functional Specification
X18A-A-001-08
Issue Date: 01/01/29
The following two tables summarize the maximum value of the Line Byte Count Register for different
display 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.
Refer to Power Save Modes on page 77 for a complete Power Save Mode description.
bit 5
LCD Signal State
When this bit = 0, all LCD interface signals are forced low during Power Save modes. When this bit = 1,
all LCD interface signals are forced to a high impedance (Hi-Z) state during Power Save modes. This bit
goes low on RESET.
bit 4
LUT Bypass
When the LUT Bypass bit = 0, the Look-Up Table is used for display data output in gray shade modes.
When this bit = 1, the Look-Up Table is bypassed for display data output in gray shade modes (for power
save purposes). There is no effect on changing this bit in BW and color modes. In BW display mode, the
Look-Up Table is always bypassed and in color display mode the Look-Up Table cannot be bypassed. The
LUT Bypass bit goes low on RESET.
Table 8-3: Maximum Value of Line Byte Count Register - 8-Bit Display Memory Interface
Display Modes
Maximum Value of
Line Byte Count Register
Corresponding Maximum
Number of Pixels in One
Display Line
black-and-white (BW)
0FFh
256 x 8 = 2048
4-level gray shade / 4 colors
0FFh
256 x 4 = 1024
16-level gray shade / 16 colors
1FFh
512 x 2 = 1024
Table 8-4: Maximum Value of Line Byte Count Register - 16-Bit Display Memory Interface
Display Modes
Maximum Value of
Line Byte Count Register
Corresponding Maximum
Number of Pixels in One
Display Line
black-and-white (BW)
0FFh
256 x 16 = 4096
4-level gray shade / 4 colors
0FFh
256 x 8 = 2048
16-level gray shade / 16 colors
0FFh
256 x 4 = 1024
256 colors
1FFh
512 x 2 = 1024
AUX[03] Mode Register 1
I/O address = 0011b, Read/Write
PS
Bit 1
PS
Bit 0
LCD Signal
State
LUT
Bypass
LCD Data
Width Bit 1
BW /
256 colors
Color Mode
Line Byte
Count Bit 8
Table 8-5: Power Save Mode Selection
PS1
PS0
Mode Activated
0
0
Normal Operation
0
1
Power Save Mode 1
1
0
Power Save Mode 2
1
1
Reserved
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