Hi, i was looking at the pinout for some atmegas today 64 and 32 and i noticed two pins that confused me.
PEN pin one on the mega64 has a description in pin definitions:
This is a programming enable pin for the SPI Serial Programming mode. By holding this pin low
during a Power-on Reset, the device will enter the SPI Serial Programming mode. PEN is internally
pulled high. The pullup is shown in Figure 22 on page 52 and its value is given in Section
“DC Characteristics” on page 325. PEN has no function during normal operation.
What exactly does this mean? That i have to hold it low to program the device?
Also, i found this on avr freaks but it didn't quite set it out for me:http://www.avrfreaks.net/index.php?name=PNphpBB2&file=viewtopic&p=340086
The other pin that confused me was "SS", pin ten on the mega64.
It had no definition in the pin description area... I have read around and found it may have something to do with I2c?
Any help would be greatly appreciated.