Так в мануалі все гарно:
The System Reset of ENC28J60 can be accomplished
by either the RESET pin, or through the SPI interface.
The RESET pin provides an asynchronous method for
triggering an external Reset of the device. A Reset is
generated by holding the RESET pin low. The
ENC28J60 has a noise filter in the RESET path which
detects and ignores small pulses of time, tRSTLOW, or
less.
When the RESET pin is held high, the ENC28J60
will operate normally
То був натяк
