Parallax SX Second Look

microcontrollerusermicrocontrolleruser Posts: 1,194
edited 2018-03-17 - 06:03:03 in Microcontrollers

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.


  • AleAle Posts: 2,352
    Aren't SX chips like 4 times faster at the same clock speed ?

  • You brought up a good point.

    Microchip NEVER tried to up the speed of their PIC's in all these years.

    They did it gradually but never seemed to make it a priority.

    You have to look at what a lot of micro's are used for mostly.

    They can build a huge amount of products and run at kilohertz and it won't matter.

    You get into digital processing then it's a different story.

  • There's something good about SX assembler. I just cannot get a handle on it.

    This might have been a glimmer here.

    It has JMP and a wide open MOV.

    I think this might be a link to the 'first out of the blocks' original microcontrollers languages.

    MOV is just MOV. Has arguments following it. Very flexible.

    PIC MOV is MOVLW and MOVF.More baggage with those

    JMP is simple and direct as it gets.

    PIC GOTO is okay. I think JMP sticks with you more.

    Going to look into 'JUMPING' between SX's and PIC's in a constructive way.

    At first look it seems like it would just throw you off but it might work out.
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