PIC18LF67K40PIC18LF8520 PIC18LF8525 PIC18LF8527 PIC18LF8585 PIC18LF8620 PIC18LF8621 PIC18LF8622 PIC18LF8627 PIC18LF8628 PIC18LF8680 PIC18LF8720 PIC18LF8722 PIC18LF8723
All VSS and VDD pins must be connected. Even if one of these pins is not connected, programming may fail.
Since NSDSP is a Low-Voltage Programmer (LVP), it can only program PIC devices if LVP configuration bit is enabled. Fresh (unprogrammed) devices have LVP bit set and therefore they can be programmed. It is impossible to disable LVP bit during LVP programming, but if the device has been previously programmed with HVP programmer, the LVP bit may have been disabled.
When brown-out is enabled with BOREN configuration bit, LVP is only possible when the VDD voltage is above the brown-out threshold.
These limitations may be avoided with High-Voltage Programming (HVP), however NSDSP requires an external circuit for HVP.
Target Voltage below 2.7V
If voltage is less than 2.7V it is impossible to bulk erase the device. Unless the PIC device is code protected, NSDSP still can program the device, however, without the bulk erase it takes longer.
NSDSP cannot detect target voltage and it assumes that the voltage is above 2.7V. This ensures fast programming at usual voltages. However, if you want to program at voltages below 2.7V, you must specify the actual target voltage through programming software, or the programming will fail. If you specify the voltage below 2.7V NSDSP will apply special programming algorithm, which does not use bulk erase, but is slower than the regular algorithm.
If you are programming a device which is code protected, NSDSP cannot remove protection if the voltage is below 2.7V.
When programming at voltages below 2.7V, NSDSP tries to save time, and therefore does not erase data EEPROM unless some part of data EEPROM needs to be programmed. If erasing data EEPROM is necessary, you can erase the device manually before programming.
NSDSP firmware contains all the necessary provisions for debugging PIC18LF67K40 with NSDS. Once NSDS support for this device is compliete, NSDS will be able to debug it.
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