Description; S5U13503B00C Evaluation Board Display Memory - Epson S1D13503 Technical Manual

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4.2 Description

When displaying an image, the S1D13503 must read pixel data from display memory. This memory is organized to match
the display resolution of the given LCD panel. To organize display memory, the following registers must be programmed:
1. Screen 1 Display Start Address Registers
2. Screen 2 Display Start Address Registers
3. Address Pitch Adjustment Register
For the first example, the Address Pitch Adjustment Register is programmed to zero. This means that no virtual display is
available; for information on virtual displays see Section 5.1, "Virtual Displays" on page 40.

4.2.1 S5U13503B00C Evaluation Board Display Memory

There are several issues to consider when programming the Screen Display Start Address Registers for the S5U13503B00C
evaluation board:
• The S5U13503B00C is always set for 128k of display memory. This memory exists as two 64k banks at addresses
D000:0000h to D000:FFFFh. To access bank 0, read from the base port address + 2. To access bank 1, write to base
port address + 2. The values read from or written to base port address + 2 are not important. The start of bank 0 repre-
sents the top left corner of display memory.
• For the S5U13503B00C, the Screen Display Start Address Registers are always in reference to the display memory
address D000:0000h, bank 0. Writing 0 to a Display Start Address Register will always refer to D000:0000h, bank 0.
• Although the S1D13503 can set the Memory Interface to 8 or 16 bits, the S5U13503B00C evaluation board must be
set for 16 bits in order to access 128k of display memory. As a result, the Display Start Address Registers are word
pointers, not byte pointers. To illustrate how to use a word pointer, refer to Example 8. In general, any system which
uses more than 64k of display memory must always have the Memory Interface set to 16 bits.
Example 8:
Location D000:0000h bank 1 refers to the start of the second 64k bank of display memory. Consequently the start address
is 10000h bytes (64k), or 8000h words.
START ADDRESS[LSB] = 00h
START ADDRESS[MSB] = 80h
S1D13503
X18A-G-002-06
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For the S5U13503B00C, calculate the required start address register value which refers
to location D000:0000h, bank 1.
Epson Research and Development
Vancouver Design Center
Programming Notes and Examples
Issue Date: 01/01/30