Acrosser AR-B1565 - Manual (Page 8)

AR-B1565/1565A User’s Guide
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2. SYSTEM CONTROLLER
This chapter describes the main structure of the AR-B1565/1565A CPU board. The topics are covered as follow:
! Microprocessors
! DMA Controller
! Keyboard Controller
! Interrupt Controller
! Serial Port
! Parallel Port
2.1 MICROPROCESSOR
The AR-B1565/1565A uses the NS GEODE GX1 CPU; it is an advanced 32-bit x86 compatible processor offering
high performance, with fully accelerated 2D graphics, a 64-synchronous DRAM controller and a PCI bus controller,
all on a single chip. This latest generation of the Media GX processor enables a new class of premium
performance notebook/desktop, and IPC computer designs.
The Media GX MMX with enhanced processor companion chips not only provide advanced video and audio
functions but also permit direct interface to memory. This high-performance 64-bit processor is x86 instruction set
compatible and supports MMX technology.
This processor is the latest member of the NS Media GX family, offering high performance; with fully accelerated
2D graphics, synchronous memory interface and a PCI bus controller, all on a single chip. As described in
separate manuals, the CS5520 and the CS5530 I/O Companion chips fully enable the features of the Media GX
processor with MMX support. These features include full VGA and VESA video, 16-bit stereo sound, IDE interface,
ISA interface, SMM power management, and AT compatibility logic. In addition, the newer CS5530 is AC97
Version 2.0 audio compliant that provides an Ultra DMA/33 interface, MPEG2 assist.
In addition to the advanced CPU features, the Media GX processor integrates a host of functions in which typically
implemented with external components. A full-function graphics accelerator provides pixel processing and
rendering functions.
The NS Media GX MMX-Enhanced Processor represents a new generation of x86-compatible 64-bit
microprocessors with sixth-generation features. The decoupled load/store unit (within the memory management
unit) allows multiple instructions in a single clock cycle. Other features include single-cycle execution, single-cycle
instruction decode, 16KB write-back cache, and clock rates up to 300MHz. These features are possible by the use
of advanced-process technologies and super pipelining.
2.2 DMA CONTROLLER
The equivalent of two 8237A DMA controllers are implemented on the AR-B1565/1565A board. Each controller is
a four-channel DMA device that will generate the memory addresses and willcontrol 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 to transfer to 8-
bit peripherals (DMA1) and three channels to 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 information for the DMA channels:
Slave with four 8-bit channels Master with three 16-bit channels
DMA Controller 1 DMA Controller 2
Channel 0: Spare Channel 4(0): Cascade for controller 1
Channel 1: IBM SDLC Channel 5(1): Spare
Channel 2: Diskette adapter Channel 6(2): Spare
Channel 3: Spare Channel 7(3): Spare
DMA Channel Controller