Epson Research and Development
Page 85
Vancouver Design Center
Hardware Functional Specification
S1D13503
Issue Date: 01/01/29
X18A-A-001-08
9.4 Memory Size Calculation
Memory Size (bytes) =
Example : For a 640x480, 4 gray shades (2 bits-per-pixel) system :
Memory Size (bytes) =
9.5 Memory Size Requirement
The following tables summarize the preceding information (formulae).
Input clock (f
OSC
) is limited by SRAM access time depending on the display mode and display memory interface that is
being used. As a result, different resolutions will have different input clock and memory requirements for a particular frame
rate. Tables 9-3 through 9-5 summarize the minimum memory size and access time requirements for various resolutions at
a particular input clock along with the corresponding frame rates.
(1) Memory more than 128KB cannot be supported by S1D13503.
(2) Memory more than 64KB can only be supported through 16-bit display memory interface.
(3) 256 color mode must use 16-bit display memory interface.
* KB = K byte = 1024 bytes
Table 9-3: Memory Size Requirement: Number of Horizontal Pixels = 640
Number of Horizontal Pixels = 640
Display
Mode
Black-and-White
(BW)
(1 bit-per-pixel)
4 Grays / 4 Colors
(2 bits-per-pixel)
16 Grays / 16 Colors
(4 bits-per-pixel)
256 Colors
(8 bits-per-pixel)
Condition AUX[0C] = AUX[02]
AUX[0C] = 0
AUX[0C] = 0
AUX[0C] = 0
Example
Display
Memory
Interface
Size
Access Time
Size
Access Time
Size
Access Time
Size
Access Time
Input
Clock
(f
OSC
)
Frame Rate
(KB) 3V/3.3V
5V
(KB) 3V/3.3V
5V
(KB) 3V/3.3V
5V
(KB) 3V/3.3V
5V
BW /
Gray
Color
480
8-bit
16-bit
37.5
40 ns
125 ns
55 ns
140 ns
75
(2)
125 ns
(2)
140 ns
150
(1)
(1)
300
(1)
(1)
24 MHz 76 Hz
74 Hz
400
8-bit
16-bit
32
60 ns
160 ns
75 ns
175 ns
62.5
60 ns
160 ns
75 ns
175 ns
125
(2)
60 ns
(2)
75 ns
250
(1)
(1)
20 MHz 75 Hz
74 Hz
320
8-bit
16-bit
25
85 ns
210 ns
100 ns
225 ns
50
85 ns
210 ns
100 ns
225 ns
100
(2)
85 ns
(2)
100 ns
200
(1)
(1)
16 MHz 75 Hz
73 Hz
256
8-bit
16-bit
20
125 ns
290 ns
140 ns
305 ns
40
125 ns
290 ns
140 ns
305 ns
80
(2)
125 ns
(2)
140 ns
160
(1)
(1)
12 MHz 70 Hz
69 Hz
240
8-bit
16-bit
19
125 ns
290 ns
140 ns
305 ns
37.5
125 ns
290 ns
140 ns
305 ns
75
(2)
125 ns
(2)
140 ns
150
(1)
(1)
12 MHz 75 Hz
73 Hz
200
8-bit
16-bit
16
160 ns
360 ns
175 ns
375 ns
32
160 ns
360 ns
175 ns
375 ns
62.5
60 ns
160 ns
75 ns
175 ns
125
(2)(3)
60 ns
(2)(3)
75 ns
10 MHz 75 Hz
73 Hz
HorizontalPixels
(
)
VerticalLines
(
)
BitsPerPixel
(
)
×
×
8
------------------------------------------------------------------------------------------------------------------------------------------------
640
(
)
480
(
)
2
( )
×
×
8
------------------------------------------------
76800bytes
75Kbyte
=
=
N
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