W65C832_1 Datasheet, PDF (22/64 Pages) –

WDC
THE WESTERN DESIGN CENTER, INC.
W65C832
2.14 Valid Data Address (VDA) and Valid Program Address (VPA)
These two output signals indicate valid memory addresses when high logic 1, and are
used for memory or IIO address qualification.
VDA VPA
o 0 Internal Operation-Address and Data Bus available.
The Address Bus may be invalid.
o 1 Valid program address-may be used for program cache
control.
1 0 Valid data address-may be used for data cache control.
1 1 Opcode fetch-may be used for program cache control
and single step control
2.15 VDD and VSS
VDD is the positive supply voltage and VSS is system logic ground.
2.16 Vector Pull (VP-)
The Vector Pull output indicates that a vector location is being addressed during an
interrupt sequence. VP- is low during the last two interrupt sequence cycles,
during which time the processor reads the interrupt vector. The VP- signal may be
used to select and prioritize interrupts from several sources by modifying the
vector addresses.
MARCH 1990
14