I'm working on a custom Blackfin 533 board which is broadly based on the EZ-Kit implementation. The reset line of the Blackfin is controlled by an ADM6316 circuit (without the WDI utilised). Its a very simple reset circuit, the output of which is shared between the Blackfin and an M29W320DB70N3 flash device. At a certain point in my software programme, occasionally the reset line goes low (seen on a scope) and the processor resets. The Blackfin documentation shows the reset line as an input only and I assume it cannot be asserted from the processor. I'm at a loss as to how the reset line is being pulled low but can you confirm that, if the processor undergoes an internal software reset, the physical reset line is not capable of being pulled low by the processor?
Many thanks for your assistance.
Its always the same, you finally decide to ask for assistance and then the answer makes itself obvious. This ADM6316 is specified for a 3.1V reset threshold and is far too close to the 3.3V rail. A simple device substitute and the problem should be fixed. Thanks anyway