AD7885 AD [Analog Devices], AD7885 Datasheet - Page 12

• Manufacturer Part Number: AD7885
• Description: LC2MOS 16-Bit, High Speed Sampling ADCs
• Manufacturer: AD [Analog Devices]

AD7884/AD7885
The second way is to use the BUSY output of the AD7884 to
generate an interrupt in the MC68000. Because of the nature of
its interrupts, the MC68000 requires additional logic (not
shown in Figure 18) to allow it to be interrupted correctly. For
full information on this, consult the MC68000 User’s Manual.
AD7884 to 80286 Interface
The 80286 is an advanced high performance processor with spe-
cial capabilities aimed at multiuser and multitasking systems.
82284 CLOCK
GENERATOR
CLK
Figure 19. AD7884 Interfacing to Basic iAPX 286 System
CLK
CLK
CONTROLLER
82288 BUS
D
80286
CPU
15
A
– D
23
MRDC
0
– A
0
–12–
TRANSCEIVER
8286 OR 8287
Figure 19 shows an interface configuration for the AD7884 to
such a system. Note that only signals relevant to the AD7884
are shown. For the full 80286 configuration refer to the iAPX
286 data sheet (Basic System Configuration).
In Figure 19 conversion is started by writing to a selected ad-
dress and causing it CS2 to go low. When conversion is com-
plete, BUSY goes high and initiates an interrupt. The processor
can then read the conversion result.
CONTROLLER
CIRCUITRY
DECODE
INTERRUPT
8282 OR
LATCH
8283
8259A
CS1
CS2
MEMORY READ
IR – IR
0
7
RD
CS
CONVST
DB15
DB0
AD7884
BUSY
REV. C