MA82380 View Datasheet(PDF) - Intel

Part Name

Description

Manufacturer

MA82380

HIGH PERFORMANCE 32-BIT DMA CONTROLLER WITH INTEGRATED SYSTEM SUPPORT PERIPHERALS

Intel 

M82380

1 0 FUNCTIONAL OVERVIEW

The M82380 contains several independent function-

al modules The following is a brief discussion of the

components and features of the M82380 Each

module has a corresponding detailed section later in

this data sheet Those sections should be referred

to for design and programming information

1 1 M82380 Architecture

The M82380 is comprised of several computer sys-

tem functions that are normally found in separate

LSI and VLSI components These include a high-

performance eight-channel 32-bit Direct Memory

Access Controller a 20-level Programmable Inter-

rupt Controller which is a superset of the M8259A

four 16-bit Programmable Interval Timers which are

functionally equivalent to the M82C54 timers a

DRAM Refresh Controller a Programmable Wait

State Generator and system reset logic The inter-

face to the M82380 is optimized for high-perform-

ance operation with the i386 microprocessor

The M82380 operates directly on the i386 micro-

processor bus In the Slave Mode it monitors the

state of the processor at all times and acts or idles

according to the commands of the host It monitors

the address pipeline status and generates the pro-

grammed number of wait states for the device being

accessed The M82380 also has logic to reset the

i386 microprocessor via hardware or software reset

requests and processor shutdown status

After a system reset the M82380 is in the Slave

Mode It appears to the system as an I O device It

becomes a bus master when it is performing DMA

transfers

To maintain compatibility with existing software the

registers within the M82380 are accessed as bytes

If the internal logic of the M82380 requires a delay

before another access by the processor wait states

are automatically inserted into the access cycle

This allows the programmer to write initialization rou-

tines etc without regard to hardware recovery

times

Figure 1 shows the basic architectural components

of the M82380 The following sections briefly dis-

cuss the architecture and function of each of the

distinct sections of the M82380

Figure 1 Architecture of the M82380

271070 – 2

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