GPROGCan't read the data

[DAIHAI]

，The pin has been tested. There is something wrong with PA15. Is there any way to determine whether it is the equipment or something wrong?

[IKS]

PA15 is not used

"no response from the device":
- Check that the programmer driver is installed correctly. The recommended driver can be found on
the store website, on the GromCalcTool forum and in the programmer menu. The programmer will
not work over UART with drivers downloaded from unknown sources or automatically updated by
Windows.
- The driver version must be strictly: 6.7.4.261 19.09.2016.  https://t.me/gcthelp/86
- When working with locked 1330A microcontrollers, disable all glitch lines first and make sure you
can get a response from the MCU over UART.
- Understand that if you are not supplying external 12 V power, then 3.3VCC and 1.2V core power
must be connected.
Try changing the chip reading settings: baudrate / portdelay. Check the contacts on the
programmer connector and ribbon cable, as well as correct connection to the board/processor. A
very common problem is long wires going from the programmer to the processor (normal length is
no more than 12 cm, without intermediate sockets, twisted joints, adapters, etc.). If you do not want
to remove long “flying” wires, the power problem from the programmer can be solved by using an
external power supply for the unit; in this case, do not connect the programmer’s VCC to the board,
but do connect GND (not applicable to Lock 1330A). Disconnect external power before and after
changing between read/write operations.
b) "Check frequence":
- Check the configured frequency of the processor (it can be determined by the nearby crystal or
from the datasheet).
c) "check VCC 5 or 3.3v":
- Check that the VCC voltage is set correctly to 3.3 V or 5 V (according to the processor datasheet).
Note that this voltage is taken from the computer’s USB port; if the port outputs less than required,
the programmer cannot boost it and the voltage loss may be caused by a long and/or low-quality
USB cable (a 1 m cable works fine; 2–3 m will cause problems).
d) In some cases the reading/writing problem is solved by swapping RX and TX lines. (Tx –
transfer: data from us to the device; Rx – receive: data from the device to us). It is logically clear
that when connecting devices A and B, Tx(A) must be connected to Rx(B) and Rx(A) to Tx(B).
Therefore in some connection diagrams to the processor, the pinout may be indicated at the
developer’s discretion, and you must use logic or simply swap RX/TX.