The 8051 featured a still reasonably respectable 4k of ROM and 128 bytes of RAM – not too dissimilar from an ATtiny of today until you realize this 30-year-old chip has 32 IO pins. This ...

This new SWORD single-wire debug makes the 8051 core even more resource-efficient, saving three pins over JTAG yet still providing complete debugging capabilities.” The SWORD interface works with the ...