AN2414 Freescale Semiconductor / Motorola, AN2414 Datasheet - Page 10

• Manufacturer Part Number: AN2414
• Description: CMOS Signal Interface (CSI) Module Supplementary Information for MC9328MX1 and MC9328MXL Application Note
• Manufacturer: Freescale Semiconductor / Motorola

Statistics
5.3 Double Resolution Mode (DRM)
Double Resolution Mode allows the vertical resolution of image to be enhanced, without increasing the
complexity of hardware. User may find this useful when they fine tune the algorithm of white balance.
In the DRM mode, The number of rows of blocks are doubled, generating twice amount of statistical data.
However for each block, the height, and so the number of pixels, has been reduced to half, resulting in the
magnitude of statistical data being halved. This is already compensated by internal logic. So for the same
input pattern, suppose every pixel having the same value, enabling / disabling DRM mode would not affect
the magnitude of the statistical data in FIFO.
In case line skipping is enabled, the calculation for HSC & VSC would require a little change. Take the
case of VGA as an example:
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1. Choose the smaller closest LVRM
2. Enable DRM
3. Divide image height & width by the no. of statistical blocks
4. Subtract the statistic block size from the above
5. Offset the above numbers by 1 giving the HSC & VSC
=> LVRM Mode 0 = 512 x 384 (8 x 6 blocks, each 64 x 64 pixels)
=> 8 x 12 blocks (Each 64 x 32 pixels)
=> Horizontal : 640 / 8 = 80
=> Vertical : 480 / 12 = 80
=> Horizontal : 80 - 64 = 16
=> Vertical : 40 - 32 = 8
=> HSC : 16 - 1 = 15
=> VSC : 8 - 1 = 7
Freescale Semiconductor, Inc.
For More Information On This Product,
MC9328MX1/MXL Application Note
Engineering Draft / Preliminary
Go to: www.freescale.com
Figure 10.
MOTOROLA