8.2.1 Test Setup
Configuration used for the performance numbers are:
- Data Size used for calculation: Data transfer rates are 1Mbytes of data sent out 100 times in each of the observations.
- USB frequency:
- SuperSpeed (SS):
- Data transfer/differential Port: 5 GHz
- Configuration Port : 133 MHz
- High-Speed (HS):
- Data transfer/differential Port: 480 Mbps
- Configuration Port : 133 MHz
- L3 frequency : 133 MHz of L3 clock is used to configure the USB registers.
The USB can be used in 2 different modes: Peripheral and Host mode. For these two modes, the configuration of the test used is:
- Peripheral mode tests:
- Host PC
- Dell Precision T3600 - Xubuntu 13.10
- 2 XHCI host cards, one from NEC and one from TI
- On-board EHCI controller
- TDA2xx and TDA2ex-evm
- TDA2xx-evm running mass storage gadget with RAM backed storage for Bulk I/O tests. (Mass storage gadget are pen drives/TDA2xx and TDA2ex-evm as Storage device in case of Peripheral mode.)
- TDA2xx-evm running g_zero gadget for raw ISO I/O tests. (g_zero gadget is a linux usb test peripheral driver that has source/sink capabilities for bulk and ISO transfers. Only the ISO endpoints for the ISO throughput test are used.)
- CPU locked at 1 GHz
- Host mode tests:
- TDA2xx and TDA2ex-evm used as host
- Peripheral gadget
- OMAP5 µEVM running mass storage gadget with RAM backed storage for Bulk I/O tests. (Mass storage gadget are pen drives/TDA2xx and TDA2ex-evm as Storage device in case of Peripheral mode.)
- OMAP5 µEVM running g_zero gadget for raw ISO I/O tests. (g_zero gadget is a linux usb test peripheral driver that has source/sink capabilities for bulk and ISO transfers. Only the ISO endpoints for the ISO throughput test are used.)
- CPU locked at 1 GHz
For host bulk tests, uses the OMAP5 µEVM as a mass storage device. For host ISO tests, uses the µEVM as a g_zero gadget.
Commands used for the transactions are:
- IN: dd if=/dev/sda of=/dev/null bs=1M count=100 iflag=direct
- OUT: dd if=/dev/zero of=/dev/sda bs=1M count=100 oflag=direct