PIC12F508PIC12F509 PIC12F510 PIC12F519 PIC12F609 PIC12F615 PIC12F617 PIC12F629 PIC12F635 PIC12F675 PIC12F683 PIC12F752
Programming is impossible at voltages below 4.5V.
PIC12F508 can only be programmed with HVP (High Voltage Programming). This means it requires Vpp voltage (higher than Vdd) for programming.
NSDSP-2 generates Vpp internally and can program PIC12F508.
No device id
PIC12F508 does not have a device id. Therefore NSDSP cannot determine if it is connected to PIC12F508 or to a different device. Moreover, it is impossible to determine if NSDSP is connected to any device at all. Therefore, NSDSP will proceed with programming assuming that it is connected to PIC12F508.
With other devices, NSDSP uses device id to determine the optimal connection speed. Since the device id is missing on PIC12F508, NSDSP will always program at the maximum allowed speed.
OSCCAL calibration word
PIC12F508 requires an OSCCAL calibration word. This word is stored in program memory at the address 0x01ff. NSDSP will read the calibration word before programming and will restore it back after programming. However, if the HEX file contains data for address 0x01ff, NSDSP will not override the data with the calibration word.
PIC12F508 also stores a backup copy of factory calibration word. NSDSP may use this backup copy to replace calibration word if necessary. The backup copy will persist through bulk erase. However, when user id information is erased, the backup calibration word will be erased too and NSDSP will have to restore it after programming.
Since the calibration information must be erased and written back, any adverse event during programming operation (such as power outage) may cause the loss of calibration information.
If the PIC device does not contain the correct calibration word, NSDSP will refuse to program. In such case, you can restore the calibration word using nsprog, for example:
nsprog e -d PIC12F508 -c cxx
where "cxx" should be replaced with the desired calibration word in hexadecimal format.
When reading from PIC12F508, NSDSP does not read the OSCCAL calibration information, however the calibration information can be retrieved with nsread, for example:
nsread 01ff 0200 -d PIC12F508
NSDSP cannot be used to debug PIC12F508.
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