PIC18LF4455PIC18LF4458 PIC18LF448 PIC18LF4480 PIC18LF44J10 PIC18LF44J11 PIC18LF44J50 PIC18LF44K22 PIC18LF4510 PIC18LF4515 PIC18LF452 PIC18LF4520 PIC18LF4523 PIC18LF4525 PIC18LF4550 PIC18LF4553 PIC18LF458 PIC18LF4580 PIC18LF4585 PIC18LF45J10 PIC18LF45J11 PIC18LF45J50 PIC18LF45K22 PIC18LF45K40 PIC18LF45K42 PIC18LF45K50 PIC18LF45K80 PIC18LF4610 PIC18LF4620 PIC18LF4680 PIC18LF4682 PIC18LF4685 PIC18LF46J11 PIC18LF46J13 PIC18LF46J50 PIC18LF46J53 PIC18LF46K22 PIC18LF46K40 PIC18LF46K42 PIC18LF46K80 PIC18LF47J13 PIC18LF47J53 PIC18LF47K40 PIC18LF47K42 PIC18LF55K42 PIC18LF56K42 PIC18LF57K42 PIC18LF6520 PIC18LF6525 PIC18LF6527 PIC18LF6585 PIC18LF65K40 PIC18LF65K80 PIC18LF6620 PIC18LF6621 PIC18LF6622 PIC18LF6627 PIC18LF6628 PIC18LF6680 PIC18LF66K40 PIC18LF66K80 PIC18LF6720 PIC18LF6722 PIC18LF6723 PIC18LF67K40 PIC18LF8520 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 BOR 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 3.0V
If voltage is less than 3.0V 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 3.0V. This ensures fast programming at usual voltages. However, if you want to program at voltages below 3.0V, you must specify the actual target voltage through programming software, or the programming will fail. If you specify the voltage below 3.0V 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 3.0V.
When programming at voltages below 3.0V, 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.
Alternative ICSP pins in TQFP-44 package
TQFP-44 package has additional dedicated ICSP pins. They may be used to free up regular ICSP pins. Functioning of both regular and alternative ICSP pins is controlled by the ICPRT configuration bit according to the following table.
|ICSP Pins||ICPRT=0||ICPRT=1||Regular||LVP, HVP, Debug||HVP only||Alternative||Disabled||HVP, Debug|
LVP = Low Voltage Programming, HVP = High Voltage Programming.
According to Microchip documentation, the default state of the ICPRT bit is 0. However, all the devices which we used for our tests came with ICPRT programmed as 1. This means that new devices cannot be programmable through LVP regardless of which sets of pins is used.
NSDSP firmware contains all the necessary provisions for debugging PIC18LF4455 and may be debugged when debugging software becomes available.
© 2007-2018 Northern Software Inc. All Rights Reserved.