sed1355 ETC-unknow, sed1355 Datasheet - Page 129

• Manufacturer Part Number: sed1355
• Description: Sed1355 Embedded Ramdac Lcd/crt Controller
• Manufacturer: ETC-unknow

Epson Research and Development
Vancouver Design Center
9 Display Buffer
Hardware Functional Specification
Issue Date: 99/05/18
CS#
0
0
1
512K Byte Buffer
The system addresses the display buffer through the CS#, M/R#, and AB[20:0] input pins. When
CS# = 0 and M/R# = 1, the display buffer is addressed by bits AB[20:0]. See the table below:
The display buffer address space is always 2M bytes. However, the physical display buffer may be
either 512K bytes or 2M bytes – see “Summary of Configuration Options”.
The display buffer can contain an image buffer, one or more Ink/Cursor buffers, and a half-frame
buffer.
A 512K byte display buffer is replicated in the 2M byte address space – see the figure below.
Ink/Cursor Buffer
Half-Frame Buffer
Ink/Cursor Buffer
Half-Frame Buffer
Ink/Cursor Buffer
Half-Frame Buffer
Ink/Cursor Buffer
Half-Frame Buffer
Image Buffer
Image Buffer
Image Buffer
Image Buffer
M/R#
X
0
1
Figure 9-1: Display Buffer Addressing
Table 9-1: SED1355 Addressing
Register access:
• REG[00h] is addressed when AB[5:0] = 0
• REG[01h] is addressed when AB[5:0] = 1
• REG[n] is addressed when AB[5:0] = n
Memory access: the 2M byte display buffer is addressed by
AB[20:0]
SED1355 not selected
AB[20:0]
17FFFFh
000000h
07FFFFh
080000h
0FFFFFh
100000h
180000h
1FFFFFh
Access
Half-Frame Buffer
Ink/Cursor Buffer
2M Byte Buffer
Image Buffer
X23A-A-001-11
SED1355
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