AR-B1380/AR-B1380A User’ s Guide
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2. SYSTEM CONTROLLER
This chapter describes the major structure of the AR-B1380/AR-B1380A CPU board. The following topics
are covered:
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Microprocessor
l
DMA Controller
l
Keyboard Controller
l
Interrupt Controller
l
Real-Time Clock and Non-Volatile RAM
l
Timer
l
Serial Port
l
Parallel Port
l
Solid State Disks
l
Ethernet Controller
l
VGA Controller
2.1 MICROPROCESSOR
The AR-B1380/AR-B1380A uses the ALI M6117 CPU. It is designed to perform like Intel’ s 386SX system
with deep green features.
The 386SX core is the same as the M1386SX of Acer Labs. Inc. and 100% object code compatible with
the Intel 386SX microprocessor. System manufacturers can provide 386 CPU based systems optimized
for both cost and size. Instruction pipelining and high bus bandwidth ensure short average instruction
execution times and high system throughput. Furthermore, it can minimize charge leakage while the
external clock is stopped, without storing the data in registers. The power consumption here is almost zero
when the clock stops. The internal structure of this core is 32-bit and it’ s address bus with a very low
supply current. Real mode as well as protected mode are available and can run MS-DOS, MS-Windows,
OS/2 and UNIX.
2.2 DMA CONTROLLER
The equivalent of two 8237A DMA controllers are implemented in the AR-B1380/AR-B1380A CPU board.
Each controller is a four-channel DMA device that will generate the memory addresses and control signals
necessary to transfer information directly between a peripheral device and memory. This allows high speed
information transfer with less CPU intervention. The two DMA controllers are internally cascaded to provide
four DMA channels for transfers to 8-bit peripherals (DMA1) and three channels for transfers to 16-bit
peripherals (DMA2). DMA2 channel 0 provides the cascade interconnection between the two DMA devices,
thereby maintaining IBM PC/AT compatibility.
The following is the system DMA channel.
DMA Controller 1
DMA Controller 2
Channel 0: Spare
Channel 4: Cascade for controller 1
Channel 1: IBM SDLC
Channel 5: Spare
Channel 2: Diskette adapter
Channel 6: Spare
Channel 3: Spare
Channel 7: Spare
Table 2-1 DMA Channel Controller
Summary of Contents for AR-B1380
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