XK1 schematic and LS1 Booting procedures

[Joe]

Hi there, the power-on reset circuit for both RST_N and TRST_N is required to provide reliable booting. The XK-1 has additional caps soldered to it as a post assembly modification to ensure this thereby implementing an RC reset arrangement as mentioned.

Using an RC filter type arrangement directly on the TRST_N and RST_N pins is not recommended as the pullup behaviour on these pins can vary significantly (see errata at end of L1 datasheets). It is also not a great way of doing a reset as it doesn't cover brownouts etc. All MODE pins have pullups, I will make sure the pullup/down info gets into the next datasheet revision.

Basically the device always needs a RST_N and TRST_N at power up to ensure it is in a clean state in order to boot reliably.

Cheers,
Joe