Difference between revisions of "CW308T-AURIX"

Power Supply

The core of the TC233LP chip runs from a 1.3v supply that is generated from an on-board regulator. The I/O buses are supplied with 3.3v.

Clock

The TC233LP currently requires a 20MHz clock from the ChipWhisperer. The PLL is setup to run at x1 speed (so still 20MHz).

Security Features

The TC233LP has an additional Lockstep core that runs the same instructions as the Master core (CPU0). The outputs of these cores are compared and mismatches are reported in the Safety Management Unit of the chip. This feature can only be enabled by editing the boot header of the hex file you program the chip with.

Programming

Programming of the AURIX board can currently only be done over JTAG with the Infineon DAP miniWiggler v3 using Infineon Memtool. To program the AURIX chip, begin by plugging in the miniWiggler to J6 on the CW308 board. Next, open Memtool.

Next, you'll need to add a target for the TC233LP chip. Navigate to Target > Browse and hit New. Select "Use a default target configuration" and find "Application Kit with TC234 (DAS)" under "Application Kits (DAS)", then hit "Finish". Hit "Connect". If "Ready for Memtool Command" appeared next to it, everything went smoothly.

To actually program the device, open your hex file using "Open File..." on the left hand side. Click on the address beginning with 0xA0000000 and hit "Add Sel.>>". Finally, hit Program. Press the nRST button on the CW308. Current versions of the HAL will light up LED1 upon starting, so if this LED is on, your program has been successfully flashed.

Building Projects

To build projects for the TC233LP, you'll need HighTec's Tricore Tool Chain. Once the toolchain is installed, you'll need to add it to your path.

Once that's done, standard ChipWhisperer projects should build with make PLATFORM=CW308_AURIX CRYPTO_TARGET=TINYAES128C.

Modifying Boot Header

To access some features of the TC233LP, such as the Lockstep control and disabling boot pins, the boot header at the beginning of the hex file must be modified. One way to do this is to use the "Edit" button in Memtool. After selecting the first memory range (should begin with 0xA0000000), hit "Edit". Most of the important settings (including lockstep control and boot control) are in the final 2 bytes of the second word (address 0xA0000004).

After modifying the boot header, you'll need to calculate the CRC32 of the header for addresses 0xA0000000 to 0xA0000017, as well as its compliment (bitwise NOT). A resource like https://www.lammertbies.nl/comm/info/crc-calculation.html can be used to calculate the CRC. Make sure the input type is hex. The CRC32 should go in address 0xA0000018, while its compliment should go in address 0xA000001C. For example, the full boot header for lockstep enabled operation should be: 00000000 B3590170 00000000 00000000 00000000 00000000 964C0E85 69B3F17A.

Note that the boot header must be manually edited each time a project is recompiled. One way to avoid this is to edit the startup file that sets the boot header. This is included in the hal/aurix folder in ChipWhisperer's firmware directory as crt0-tc2x.S. The boot header can be found on lines 72 to 79. Note that the CRC32/compliment still has to be calculated for lines 72 to 77, replacing the values of lines 78 and 79.

If LED1 does not illuminate after changing the boot header, something in the header (like the CRC32) is likely incorrect.

Schematic and Layout

See GIT Repo for design files.

Hardware