3.3.5.4.1 Connecting to an AVR SPI Target
The recommended pinout for the 6-pin SPI connector is shown in 3.3.5.4.2 AVR SPI Pinout.
Connection to a 6-pin 100-mil SPI Header
Use the AVR 6-pin adapter board to connect to a standard 100-mil SPI header.
Connection to a 6-pin 50-mil SPI Header
Use the AVR 6-pin mini adapter board to connect to a standard 50-mil SPI header.
The SPI interface is effectively disabled when the debugWIRE Enable (DWEN) fuse is programmed, even if the SPIEN fuse is also programmed. To re-enable the SPI interface, the ‘disable debugWIRE’ command must be issued while in a debugWIRE debugging session. Disabling debugWIRE in this manner requires that the SPIEN fuse is already programmed. If MPLAB X IDE fails to disable debugWIRE, it is probably because the SPIEN fuse is NOT programmed. If this is the case, it is necessary to use a high-voltage programming interface to program the SPIEN fuse.
Follow the instructions in the popup window that appears.
The SPI interface is often referred to as “ISP” since it was the first in-system programming interface on Microchip AVR products. Other interfaces are now available for in-system programming.