Network MIPS-board (preliminary)
The network MIPS-platform has two Ethernet channels, possesses the advanced periphery (USB, UART, I2S, AC’97, SD/MMC, IrDA) and is intended for use in the communication equipment. The presence of buffered 32-digit bus provides connection to the board of any user devices.
Range of application is single-board computers with a simultaneous output in an external and internal network, gateway screens and routers.
· MIPS32 core 300…500MHz;
· 10/100 Ethernet MAC0 and MAC1;
· USB Device and Host controller;
· UART0, UART1, UART2, UART3 (full);
· IrDA controller;
· AC’97 controller;
· I2S controllerđ;
· SSI0 and SSI1 controller;
· Secure Digital SD0 and SD1;
· SDRAM controller;
· SRAM/Flash controller;
· two LED indicators of modes.
· full-scale support of OS Linux, Windows CE, VxWorks. The presence of the big number of ready libraries and drivers of I/O devices, information storage and view, fonts, etc.;
· the optimum price/productivity relationship is provided with hardware scalability of the board – a wide range of Flash volumes (8MB…256MB), SDRAM (16MB…256MB) č CPU speed (266MHz…500MHz);
· hardware support of video, network and system interfaces by peripherals controllers integrated in CPU.
Embedded software of a board include:
· monitor YAMON (standard MIPS monitor):
o provides command line interface through RS-232;
o provides connection with the central computer through Ethernet (TFTP);
o supports work with FLASH, including operations of erasing, record and verification of any sections, including YAMON part;
o operates a configuration of OS start process, including automatic;
· Linux 2.4.20 kernel with support of all processor hardware interfaces;
· the file system JFFS2 operating in Flash. Includes:
o set of standart Linux utilities for supply of full functionality from a command line;
o graphic QT3 libraries for a usual mode and with multithreading support, including language support by means of UNICODE.
Structure of the processor module of the network board
The processor module is executed on 8-layer MPCB with the dimensions 80mm x 76mm. It has two 100-pins communication slots: integrated peripherals and user. All signals of internal peripherals controllers are outputed from the processor on the first (peripheral) slot. The buffered static bus with additional group of control signals of an external video controller (S1D13505, Epson; MB8629x, Fujitsu) with support of the resolution up to 1600x1200 points is outputed on the second (user) slot.
Management of bus-based shapers is carried out by activation of a hardware flag of the processor which should be executed before the reference to external devices. On the termination of an exchange session the flag is programmatically switched in a passive mode and the bus drivers jump in floating state. The special opportunity of compulsory switch of the bus drivers in Z-flate is provided on the part of external devices that allows to organize with the minimal delay emergency information interchange between its abonents passing by the central processor.
The processor module possesses a wide range of hardware scaling. If necessary the user can determine Flash/SDRAM volume and CPU operating frequency in the range:
· Flash – from 8MB (2xS29GL32, Spansion) to 256MB (2xS29GL01, Spansion);
· SDRAM – from 16MB (2xK4S641632, Samsung) to 256MB (2xK4S1G0632, Samsung);
· FCPU – 333MHz, 400MHz or 500MHz.
The board has DC-DC converters from a power +9V…+24V. For increase of functionality the power supply system is distributed on both modules included in a board. Interface module provides:
· +3.3V - basic digital supply;
· +5V - USB and DC‑DC supply with galvanic separation for RS‑232;
· +12V - supply of LCD panel backlights inverter.
The processor module has two own DC-DC converters:
· +1.2V - voltage of CPU core supply (for independent work of the module);
· +3.3V - voltage of CPU, Flash, SDRAM supply (for independent work of the module).
If necessary own DC-DC converters of the processor module can be switched - off, and supply is sent through the user slot from the interface module.
To provide functions of supply division of digital/analog parts of devices there is an add-in separate slot of a network connection +9V … +24V on the processor module.
Power consumption of the processor module depending on CPU speed and SDRAM makes from 1,3 W up to 2,8 W.
Cost of the componentry of an individual unit does not exceed a mark 105 $ in the minimal configuration – CPU 330MHz, Flash 8MB, SDRAM 16MB. At the use of external power supplies +1.2V č +3.3V he price of componentry can be reduced up to 85$.