Sx kEY MGS Vpp generation failed

JW13

useing SX Tech board
Sx Key rev F
IDE v3.2.3
chip SX28AC/DP-G 0720
prog SX/B Blink1 as given in SX/B manual page 26
os Windows XP
comm DB-9
power at 5.32v

program compiles ok
run gives message "Vpp generation failed"

Bean

Where you EVER able to program the SX ? Or have you always gotten this error message ?

"Power at 5.32V" measured where ? 5.32 sounds kinda high for Vdd.

Bean.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
I know what I know, don't confuse me with the facts...
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
www.hittconsulting.com
·

Guenther Daubach

For programming the SX chips, a voltage of 12V must be present at the OSC1 pin. This programming voltage (Vpp) is generated by the SX-Key/Blitz, and the SX-Key/Blitz internally checks if this voltage is available, and if it is high enough.

Reasons for a "Vpp generation failed" error usually are:

- Supply voltage too low (should be 5 Volts)
- Some additional load on the OSC1 pin, like an external clock generator (a crystal or resonator connected to OSC1 usually are no problem)
- SX chip to be programmed is defective so that Vpp is shorted to ground via the OSC1 pin
- The SX-Key/Blitz is defective (most likely the on-board switching transistor or eventually some I/O pins of the on-board SX20)

You may use an Ohmmeter to measure the resistance between the OSC1 pin (27) and ground (Vss) pin (2) (with no power supplied to the board, and the SX-Key/Blitz not connected). It should be over 500 kOhms. When it is below, remove the SX, and measure again. If it is still below, some external load is connected to OSC1, otherwise, the SX chip may be defective.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Greetings from Germany,

G

JW13

Guenther Thanks,
followed your suggestions,
with SX in socket : measured 236k without : 1M +
changed chip out : reads the same, also Vpp msg same
Next tryed the key on an SX28 Proto board : also failed with Vpp msg
odds are against all 3 devices being defective at same time,
Therefore the Sx-Key must be defective.

Bean,
if 5.32 volts is too high at output of regulator would implie that the sx-tech board was defective from the factory.

But, thanks for the help.............JW