Multimedia Daughterboard for OMAP3EVM
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Contents |
Block Diagram
Functionality
Video Encode
For video capture applications, the OMAP3 Multimedia Daughterboard uses a TI TVP5146 Digital Video Decoder, capable of decoding NTSC/PAL/SECAM signals. Video can be input either through the S-video connector or an RCA composite connector. The output of the TVP5146 is connected to the camera interface (CAM) of OMAP3, and the device is controlled by either I2C2 or I2C3 (default is I2C2)
Board Configuration
Here are board configuration details in order to proper enable and use the TVP5146 for video capture
1. I2C Selection. You can use either I2C2 or I2C3 to control the TVP5146 via resistor population.
I2C2 - populate R83 and R63
I2C3 - populate R82 and R64
TI PSP software and associated patches use I2C2 as the default.
2. Populate either R57 or R69 to determine the I2C address for the TVP5146.
R57 for address = 0xBA (default)
R69 for address = 0xB8
TI PSP software and associated patches use address 0xBA as the default.
3. Enable/disable the on board buffers to properly configure the board to use the TVP5146
Set OMAP3 GPIO134 to 0 to enable the level shifters for the OMAP3 CAM data bus. Set OMAP3 GPIO136 to 1 to disable the level shifters for the other devices connected to the OMAP3 CAM interface.
Operation
TVP5146 Power Down signal (PWDN) is controlled by GPIO_57 of OMAP3 TVP5146 Reset signal (RESETB) is controlled by both OMAP3 SYS_nRESPWRON and GPIO58. The TVP5146 is reset during a POR, and an additional hardware reset can be produced using GPIO_58 of OMAP3. TVP5146 interrupt request (INTREQ) is sent to OMAP3 via GPIO_55 TVP5146 FID/GPIO is connected to GPIO139 of OMAP3
All signals are properly level shifted to accomodate OMAP3 1.8V I/O and TVP5146 3.3V I/O.
Video Input into the TVP5146 can be achieved through the S-Video input connector (DN1), the composite connector J1, or through the component connector J3.
The 10-bit output of the TVP5146 is connected to D0-9 of the CAM interface on OMAP3.
Connections
The Multimedia Daughtercard provides 3 methods of input: Component, Composite, and S-Video.
USB Host
An SMSC USB332x USB PHY is connected to the High Speed Host Port 2 on OMAP3. OMAP3's EHCI controller can be used to communicate over the high speed ULPI bus to the USB PHY. A full size USB A connected is provided for peripheral connections.
Board Configuration
No hardware configuration is needed.
Operation
Use OMAP3 USB Host Port 2 to communicate with the SMSC USB PHY.
Reset the PHY via GPIO_135. A reset will also occur during a power-on reset event
5V VBUS is always enabled and is provided with an on-board power switch. It can provide up to 500mA of current. Fault monitoring is provided via GPIO_62.
Connections
Full sized A connector is provided for peripheral connections.
Expansion pass through
The expansion connectors that are provided on the OMAP3EVM main board are also present on the Multimedia Daughterboard with the same pinout. Note that if you use the USB Host Port2 on the pass through connectors, you must de-populate the 0 ohm resistors going to the SMSC USB PHY. See note on page 10 of the schematic for more information.
Board Information
Schematics
Board Layout
Component information
Software Patches
This patch should be applied to PSP 1.0.2 release to enable video encode and USB EHCI with the OMAP3EVM Multimedia Daughtercard.
Please refer to the documentation that comes with the PSP release (Addendum_Daughtercard_1_0_2.pdf) found in the /docs directory, for information on how to build the code to support video encoding. There is also a sample application (saMmapLoopback) available with the release that performs video encode (via composite in or S-Video) and displays it on the LCD of the OMAP3EVM.
File:PSP-1.0.2-mdc.zip: Software Patch to PSP 1.0.2 release for video in and USB EHCI
Below is a capture application to be used with the video encode patch above. This app can capture video input to a raw video file. Instructions for running the app are provided in readme.txt. A link to a YUV video player is also provided in order to play the captured video in Windows.
File:Capture.zip: Capture application for TVP5146
Support for USB EHCI additionally requires a change to u-boot. Patch is available below. To rebuild, perform the following two commands:
#make omap3evm_config #make
Reflash u-boot onto your board according to the instructions in the PSP documentation. Reflashing will delete your bootargs so be sure you know these as you will have to reenter them after reflashing.
Before powering up your board, attach a powered hub to the USB connector of the Customer Daughtercard (currently the code will only work when hub is connected before booting). After booting, you can connect any typical peripheral to the hub (mouse, flash drive), and use it normally.
File:PSP-1.0.2-mdc-u-boot.zip: u-boot patch for 1.0.2 release
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Comments
Comments on Multimedia Daughterboard for OMAP3EVM
While the above comments on the default I2C selection match with the schematic, the photo of the board in its highest resolution (although hard to tell because it's a GIF instead of a JPEG) indicate that for the Rev.B card R82 and R64 are populated to select I2C3. I assume this is now the default, as I2C3 is used to connect to the TVP5146 on the Rev.G EVM, which has the 5146 on the main board. Are there updated schematics for the Rev.B board that show the change? Should the above discussion show the differences?
--Cread 15:45, 14 January 2010 (CST)