cbscpe wrote:
Does anyone know if VPB is asserted (i.e. pulled low as it is a negated output) during the fetch of the vector of RESET as well or is it only for the interrupts. The manual is not very clear on that
Quote:
The Vector Pull active low output indicates that a vector location is being addressed during an interrupt
sequence. VPB is low during the last two interrupt sequence cycles, during which time the processor loads
the PC with the interrupt handler vector location. The VPB signal may be used to select and prioritize
interrupts from several sources by modifying the vector addresses.
Good question, as there isn't anything in the WDC literature to indicate what VPB is up to during reset. If I can remember to do so, I'll try monitoring VPB the next time I need to reset POC (it has 295 days of uptime on it right now).