Evaluation Platforms
Evaluation and Prototyping Platforms
The following boards and systems can be used for evaluation and prototyping purposes. Evaluation platforms fall into one of the following categories: Boards that have the Xtensa processor as part of an integrated circuit, and emulation systems that use FPGAs to emulate the processor. Field programmable gate arrays (FPGA) are semiconductor devices containing programmable logic that can be re-configured to emulate complex logic. Although usually slower than their counterpart, they are widely used for prototyping or small volume applications.
Emulation Platforms and Systems
Avnet Virtex-4 LX60 and LX200
Avnet offers the following development platforms for the Xilinx Virtex-4 LX FPGA that can emulate various Xtensa processor configurations. The LX60 is based on the Xilinx 4VLX60 and comes with a 10/100 Ethernet PHY, DDR memory, flash memory, serial port, and 2 x 16 character LCD panel. The MAC controller, however, needs to be implemented inside the FPGA. MAC controllers are available from different vendors. OpenCores, for example, provides a free Ethernet controller supported by Linux and other operating systems. The LX200 is based on the Xilinx XC4VLX200 and can emulate more complex processor configurations and extensions (for example the HiFi 2 Audio Engine) and provides the same components as the LX60 except for the LCD panel.
Tensilica provides a bitstream that describes the configuration data to emulate the DC232L Xtensa Diamond processor on the LX60 FPGA. Tensilica refers to this board and bitstream combination as the XTAV60 board. It also includes support for the OpenCores Ethernet MAC. For further information, please, contact Tensilica directly.
Eve ZeBu
Eve offers an emulation and verification system that can be used to emulate Xtensa processors. Similar to FPGA boards, the ZeBu system emulates the processor, but has a higher capacity to emulate larger processor configurations and additional peripherals. It also provides direct access to signals for debugging and verification.
See the Linux on ZeBu page or contact Eve directly to request additional information.
Xtensa Evaluation Platforms
Stretch S55DVKxx and S56DVKxx
Stretch provides software-configurable processors based on the Xtensa architecture. The S5000 processor supports Linux, and at 300MHz, it runs 5-10 times faster than emulation platforms. The S55DVKxx and S56DVKxx development platforms provide 10/100/1000 Ethernet, serial, PCI (only S56DVKxx), and other interfaces.
The Stretch platforms come with RedBoot as the bootloader. It can download and boot the kernel over network using TFTP or from flash. Make sure that RedBoot is configured with a valid Ethernet address or set to DHCP to obtain a valid address. The following commands load the kernel image zImage.redboot and boot the kernel:
RedBoot> load -r -b 0xd0200000 -h 192.168.1.5 zImage.redboot RedBoot> exec 0xd0200000
Note that RedBoot requires that the tftp host is in the same subnet as the board.