beaglebone-black - Flipbook - Page 65
BeagleBone Black
6.7.3 Filter Options
FB7 and**FB8** were added to assist in passing the FCC emissions test. The USB1_VBUS signal is used by the
processor to detect that the 5V is present on the connector. FB7 is populated and FB8 is replaced with a .1
ohm resistor.
6.8 PRU-ICSS
The PRU-ICSS module is located inside the AM3358 processor. Access to these pins is provided by the expansion
headers and is multiplexed with other functions on the board. Access is not provided to all of the available
pins.
All documentation is located at http://github.com/beagleboard/am335x_pru_package_
This feature is not supported by Texas Instruments.
6.8.1 PRU-ICSS Features
The features of the PRU-ICSS include:
Two independent programmable real-time (PRU) cores:
• 32-Bit Load/Store RISC architecture
• 8K Byte instruction RAM (2K instructions) per core
• 8K Bytes data RAM per core
• 12K Bytes shared RAM
• Operating frequency of 200 MHz
• PRU operation is little endian similar to ARM processor
• All memories within PRU-ICSS support parity
• Includes Interrupt Controller for system event handling
• Fast I/O interface
16 input pins and 16 output pins per PRU core. (Not all of these are accessible on the BeagleBone Black).
6.8.2 PRU-ICSS Block Diagram
6.8.3 PRU-ICSS Pin Access
Both PRU 0 and PRU1 are accessible from the expansion headers. Some may not be usable without 昀椀rst
disabling functions on the board like LCD for example. Listed below is what ports can be accessed on each
PRU.
• 8 outputs or 9 inputs
• 13 outputs or 14 inputs
• UART0_TXD, UART0_RXD, UART0_CTS, UART0_RTS
Table 6.7: P8 PRU0 and PRU1 Access
PIN PROC NAME
11
R12
GPIO1_13
pr1_pru0_pru_r30_15
(Output)
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Chapter 6. Detailed Hardware Design
