[Cryptech Tech] arm

[Jakob Schlyter]

On 20 jan 2015, at 10:07, Fredrik Thulin <fredrik at thulin.net> wrote:

> One way of being careful is what I believe Peter G. is advocating here and 
> adding an external chip with a USB host controller and a SPI interface, in the 
> hopes that the SPI interface in our main MCU has less bugs than the USB 
> interface in the main MCU (likely true IMHO).

When the HSM is the USB client, the SPI interface makes a lot of sense, but I do not think it is possible when the HSM is the USB host. As a host, the main MCU must be able to communicate with different types of devices (mass storage, HID, ...).

	jakob