PIC16F505

Support summary

• Programming - NSDSP-1 with NSHVX or NSDSP-2
• Debugging provisions - No

ICSP Connection

Programming is impossible at voltages below 4.5V.

PIC16F505 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 PIC16F505.

NSDSP-1 cannot generate Vpp. Therefore, to be programmed with NSDSP-1, PIC16F505 requires NSHVX High Voltage Extension or an external HVP circuit.

No device id

PIC16F505 does not have a device id. Therefore NSDSP cannot determine if it is connected to PIC16F505 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 PIC16F505.

With other devices, NSDSP uses device id to determine the optimal connection speed. Since the device id is missing on PIC16F505, NSDSP will always program at the maximum allowed speed.

OSCCAL calibration word

PIC16F505 requires an OSCCAL calibration word. This word is stored in program memory at the address 0x03ff. NSDSP will read the calibration word before programming and will restore it back after programming. However, if the HEX file contains data for address 0x03ff, NSDSP will not override the data with the calibration word.

PIC16F505 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 PIC16F505 -c cxx

where "cxx" should be replaced with the desired calibration word in hexadecimal format.

When reading from PIC16F505, NSDSP does not read the OSCCAL calibration information, however the calibration information can be retrieved with nsread, for example:

nsread 03ff 0400 -d PIC16F505

Programming Benchmarks

We have measured time necessary to program and verify PIC16F505.

The measurements reflect the time necessary to program/verify the entire chip, including all user programmable memory areas.

Debugging

NSDSP cannot be used to debug PIC16F505.

Links

Microchip PIC16F505 page