beaglebone-black - Flipbook - Page 25
BeagleBone Black
– Cost reduction
– Can be added by buying a TTL to USB Cable that is widely available
– Single largest cost reduction action taken
• No JTAG emulation over USB
– Cost reduction JTAG header is not populated, but can easily be mounted.
– EEPROM Reduced from 32KB to 4KB
– Cost Reduction
• Onboard Managed NAND (eMMC)
– 4GB
– Cost reduction
– Performance boost x8 vs. x4 bits
– Performance boost due to deterministic properties vs. microSD card
• GPMC bus may not be accessible from the expansion headers in some cases
– Result of eMMC on the main board
– Signals are still routed to the expansion connector
– If eMMC is not used, signals can be used via expansion if eMMC is held in reset
• There may be 10 less GPIO pins available
– Result of eMMC
– If eMMC is not used, could still be used
• The power expansion header, for battery and backlight, has been removed
– _*Cost reduction* , space reduction
– Four pins were added to provide access to the battery charger function.
• HDMI interface onboard
– Feature addition
– Audio and video capable
– Micro HDMI
• No three function USB cable
– Cost reduction
• GPIO3_21 has a 24.576 MHZ clock on it.
– This is required by the HDMI Framer for Audio purposes. We needed to run a clock into the processor
to generate the correct clock frequency. The pin on the processor was already routed to the expansion header. In order not to remove this feature on the expansion header, it was left connected. In
order to use the pin as a GPIO pin, you need to disable the clock. While this disables audio to the
HDMI, the fact that you want to use this pin for something else, does the same thing.
4.2 BeagleBone Black Features and Speci昀椀cation
This section covers the speci昀椀cations and features of the board and provides a high level description of the
major components and interfaces that make up the board. table below provides a list of the features.
20
Chapter 4. BeagleBone Black Overview
