/Action Laser 1300 Service Manual
Operating Principles
2.2.1.3 Interrupt Control
determines the priority level of the interrupt and outputs it to terminals
through
An interrupt is then sent to the CPU. If the CPU accepts the interrupt, terminals
through
all go HIGH to indicate the interrupt acceptance to
confirms that
terminals
through
are HIGH (interrupt acknowledge), then sets the VPA terminal to LOW
and informs the CPU that this is an automatic vector interrupt. This initializes the interrupt
process.
has a controller for the automatic vector interrupt.
2.2.1.4
DRAM Management
The video controller circuit uses DRAMs for the system RAM and for the V-RAM.
The DRAMs (including optional
are managed by
and
handles the main management. The
outputs
WE, and OE signals. The DRAMs
(including optional
are controlled by the CAS, WE, and OE signals from the
and
are also controlled by the
signal from the
REFRSH
RASEN
O E
A d d r e s s W E
D a t a
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SIMM
IC23
1
Figure 2-35. DRAM Management
Rev.
2-23