Datasheet for the Microchip ENC28J60, a stand-alone 10Base-T Ethernet controller with an SPI interface, as a 480 KB PDF. The -H suffix in the name is not defined, so it may be a document variant. It describes registers, buffer memory, the SPI command set, the magnetics and oscillator requirements, and electrical ratings. Repairers use it on embedded network modules to check the 25 MHz crystal, the 3.3 V supply, link LEDs and the transformer connections to the RJ45 jack.
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