In SX Microcontrollers, SX/B Compiler and SX-Key Tool, matthew180 wrote:

Greetings,

I'm trying to get a simple test program up and running on an SX28AC, here is my configuration:

Intel based HP laptop
Windows XP w/SP2
SX-Key Software v.3.2r3 (latest on the site as of yesterday)
SX-Key Programmer Rev F
Parallax USBto232 Adapter (my laptop does not have a serial port)
FTDI USB VCP Driver v. 2.0.0.0 from the FTDI website (the driver download on the parallax site is over 2 years old)
SX28AC microcontroller (28 pin dip)

All the software and drivers installed fine and the USBto232 adapter was found and made a COM1 port without problems.  I plugged the SX-Key programmer directly into the USBto232 adapter.

Circuit power is from an AC power brick that puts out 6.5VDC @ 1A (I had a 300ma adapter at first, but thought maybe the SX-Key was using more than 200ma, so I switched to the 1A adapter).  I run that into a 7805 to get the required 5VDC.  I have the SX28AC on a breadboard with the minimal configuration shown in the SX-Key manual, i.e. VDD (pin 2) to +5VDC, VSS (pin 4) gnd, MCRL (pin 28) to +5VDC via 480ohm resistor, and the SX-Key connector to VDD, VSS, OSC1, and OSC2 as indicated.  I have checked and rechecked these connections repeatedly over two 4-hour troubleshooting sessions.

I ran the SX-Key programmer software and selected COM1 (the only com port in the system) and keyed in a very simple program example from Gunther Daubach's book Programming the SX Microcontroller:

; Test 1
DEVICE    SX28AC
DEVICE    OSC4MHZ, TURBO, STACKX, OPTIONX
IRC_CAL    IRC_4MHZ
FREQ    4_000_000
RESET    0

    MOV    !RB, #%11111110
LOOP    CLRB    RB.0
    SETB    RB.0
    JMP    LOOP

This is to blink an LED which I removed from the breadboard circuit since I'm having problems.  This assembles without problems and when I hit debug I see two progress bars, one says something to the effect of "clearing..." and the other "programming...".  After which I expect to see the debug window, but it never opens.  There is a red LED on the USBto232 adapter that flashes during all of this activity.

After trying this a few time without any luck, I hit the "device" icon and tried the "Verify" button, which says "reading" with a progress bar, then I get an error message that says "Verify Failed at Oscillator".

If I do something like disconnect the power to the SX28 and SX-Key, the software says it cannot find the SX-Key on COM1, so I'm assuming some sort of communication is taking place?

I also tried setting the serial port speed to 1200 baud from 9600 (the default).  Didn't help.  No where can I find specs for any possible COM port settings, so I assume the SX-Key software sets up the COM port appropriately?

I have two SX28AC chips and I have tried them both in the circuit, each time the errors are the same.  Eventually after poking around at the software long enough and trying to debug, assemble, run, verify, read, etc. the error message comes up and says "SX-Key not found on COM1".  Closing the software and restarting it fixes this problem and puts me back to the "Verify Failed at Oscillator" error.  I cannot find any diagnostic check to ensure the software can communicate with the SX-Key and that the SX-Key checks out.

This is getting very frustrating and any insight would be greatly appreciated.  The only other thing I can think of is to try to program from my desktop computer that does have a real serial port, but I'm not very hopeful.

Thanks,
Matthew

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