- Announcement about May 10th, 2018 update and your password.
The SX 18 is pin for pin compatible with the PIC16F54. The SX28 is probably same with PIC16F57.
SX are clones of PIC's. At the time I guess they never thought there would be a problem with Microchip but then there was.
There is a company called Holtek that is still to this day clipping along with their PIC clone and looks like Microchip never bothered them about it.
SX has an RTCC at pin 3 and PIC is something else.
The Port pins all match up though.PortA 0 to 3.Port B 0 to 7. VDD and VSS pins match up.
If you want to program the two in circuit that's a problem. They use different connections for programming so that limits actual swapping into a circuit.
SX manual is a little more plain talk than Microchip datasheets.
SX and PIC assembler are very similar.PIC has 35 instructions, SX a lot more.
Very interesting to compare the two whichever one you're using.