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Figure 36 ram write speed margins – Renesas R61509V User Manual

Page 114

background image

R61509V

Target

Spec

Rev. 0.11 April 25, 2008, page 114 of 181

RAM
write

Display
operation

0

16.67

(60 Hz)

Back porch
(14 lines)

Main panel

Moving picture

display

(432 lines)

Front porch (2 lines)

Blank period

RC oscillation

±7%

Display
operation

VSYNCX

[line]

432

VSYNCX

BP = 14H

RAM write
7.4 MHz

FP = 2H

[ms]

Line processing

Figure 35 Write/Display Operation Timing via VSYNC Interface

Notes to VSYNC Interface Operation

1. The above example of calculation gives a theoretical value. Possible causes of variances of internal

oscillator should be taken into consideration. Make enough margins in setting RAM write speed for
VSYNC interface operation.

2. The above example shows the values when writing over the full screen. Extra margin will be created if

the moving picture display area is smaller than that.

0

16.67
(60 Hz)

Display
operation

16

Back porch (14 lines)

Base image

Moving picture

display

(360 lines)

Front porch (2 lines)

(16 lines)

(56 lines)

RAM
write

[line]

[ms]

432

376

BP = 14H

VSYNC

VSYNCX

FP = 2H

RC oscillation
±7%

Display
operation

RAM write
7.4MHz

Line processing

Figure 36 RAM Write Speed Margins