Epson Research and Development Page 65
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Hardware Functional Specification S1D13705
Issue Date: 02/02/01 X27A-A-001-10
Figure 8-1: Screen-Register Relationship, Split Screen
Consider an example where REG[13h], REG[12] = 0CEh for a 320x240 display system.
The upper 207 lines (CEh + 1) of the panel show an image from the Screen 1 Start Word
Address. The remaining 33 lines show an image from the Screen 2 Start Word Address.
bits 7-0 LUT Address Bits [7:0]
These 8 bits control a pointer into the Look-Up Tables (LUT). The S1D13705 has three
256-position, 4-bit wide LUTs, one for each of red, green, and blue – refer to Section 11,
“Look-Up Table Architecture” on page 71 for details.
This register selects which LUT entry is read/write accessible through the LUT Data Reg-
ister (REG[17h]). Writing the LUT Address Register automatically sets the pointer to the
Red LUT. Accesses to the LUT Data Register automatically increment the pointer.
For example, writing a value 03h into the LUT Address R egister sets the pointer to R[3].
A subsequent access to the LUT Data Register accesses R[3] and moves the pointer onto
G[3]. Subsequent accesses to the LUT Data Register move the pointer onto B[3], R[4],
G[4], B[4], R[5], etc.
Note
The RGB data is inserted into the LUT a fter the Blue data is written, i.e. all t hree colors
must be written before the LUT is updated.
REG[15h] Look-Up Table Address Register
Address = 1FFF5h Read/Write
LUT Address
Bit 7 LUT Address
Bit 6 LUT Address
Bit 5 LUT Address
Bit 4 LUT Address
Bit 3 LUT Address
Bit 2 LUT Address
Bit 1 LUT Address
Bit 0
Line 0
Line 1
(REG[0Dh], REG[0Ch]) Words
Line 0 Last Pixel Address + REG[11h] Words
Line 0 Last Pixel Address=((REG[0Dh], REG[0Ch]) +
(8(REG[04h]+1) × BPP/16))
8(REG[04h]+1) Pixels
Virtual Image
REG[11h] Words
Line=(REG[13h], REG[12h])
((REG[06h], REG[05])+1) Lines
Image 1
Image 2 (REG[0Fh], REG[0Eh]) Words
Where:
(REG[0Dh], REG[0Ch]) is the Screen 1 Start Word Address
BPP is Bits-per-Pixel as set by REG[02h] bits 7:6
REG[11h] is the Address Pitch Adjustment in Words
(REG[0Fh], REG[0Eh]) is the Screen 2 Start Word Address
(REG[13h], REG[12h]) is the Screen 1 Vertical Size
(REG[06h], REG[05h]) is the Vertical Panel Size
Words