Δiw
Δih
2048 Pixels
0° Rotation
90° Rotation
180° Rotation
270° Rotation
VBA 0°
VBA 180°
VBA 90°
VBA 270°
2048 Pixels
Δiw
Δih
Offset
= Δih Pixels
= Δih*ps Bytes
2048 Pixels
2048 Pixels
Offset
= 2048*Δih+Δiw Pixels
= (2048*Δih+Δiw)*ps Bytes
Offset
= 2048*Δiw Pixels
= 2048*Δiw*ps Bytes
Δih
Δih
Δiw
Δiw
dss-099
Public Version
www.ti.com
Display Subsystem Basic Programming Model
provides the offset values that must be added to the virtual base addresses for 90-degree,
180-degree, and 270-degree rotation. This offset is applicable only when the defined image size in the
VRFB module is greater than the actual image size, because it must be a multiple of the page width and
height. In the example discussed above, the image height was set to 256 lines, instead of 240, because
the page height was 32 lines. This offset must be added to the virtual base addresses, because the VRFB
module is not aware of the actual image size.
illustrates why this occurs and how the offset
is calculated.
Figure 7-123. Offset for VRFB Rotation
Δ
iw = Image width delta between the actual image width and the programmed image width because of the
page width
Δ
ih = Image height delta between the actual image height and the programmed image height because of
the page height:
•
Offset 90-degree:
Δ
ih pixels =
Δ
ih x ps bytes
•
Offset 180-degree: 2048 x
Δ
ih+
Δ
iw pixels = 2048 x
Δ
ih x ps+
Δ
iw x ps bytes
•
Offset 270-degree: 2048 x
Δ
iw pixels = 2048 x
Δ
iw x ps bytes
In the example given above, the delta in the image height is 256 – 240 = 16 lines (
Δ
ih = 16), whereas the
exact value of the width can be programmed (
Δ
iw = 0). In that case, the resulting offset values are:
•
YUV:
–
Offset 90-degree: 16 x 4 bytes
–
Offset 180-degree: 2048 x 16 x 4 bytes
–
Offset 270-degree: 0 bytes
•
RGB:
–
Offset 90-degree: 16 x 2 bytes
1725
SWPU177N – December 2009 – Revised November 2010
Display Subsystem
Copyright © 2009–2010, Texas Instruments Incorporated
Содержание OMAP36 Series
Страница 174: ...174 List of Tables SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 692: ...692 MPU Subsystem SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 1084: ...1084 IVA2 2 Subsystem SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 1990: ...1990 2D 3D Graphics Accelerator SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 2334: ...2334 Memory Subsystem SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 2700: ...2700 Memory Management Units SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 2868: ...2868 HDQ 1 Wire SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 2974: ...2974 UART IrDA CIR SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 3054: ...3054 Multichannel SPI SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 3462: ...3462 MMC SD SDIO Card Interface SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 3508: ...3508 General Purpose Interface SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 3584: ...3584 Initialization SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 3648: ...3648 Debug and Emulation SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...