The Demonstrate Of IEEE488 Interface Technology For Semiconductor Laser Driver

GPIB bus is a bus protocol to connect instrument, which is mainly used in the laboratory and platform test system under testing and producing condition. The machine interface of normative interface system is loaded at panel of every programmable instrument and computer respectively. They can be connected by normative bus, when set up auto test system, user can set up instrument produced by different country, different factory and in different time to be monotype platform test system including no more than 15 instrument. GPIB normative interface acquire acknowledge widely by every country for the world for the advantage of high currency, flexible and reliable information transfers when a auto test system of GPIB bus is made up, general test instrument generally adopt instrument produced by big company, but some special instrument must be designed personally GPIB interface. NAT9914 is designed to fitful the interface function defined by IEEE488.2 normative standard enacted in 1987.The chip has completely tell control, talk, listen function and is compatible with μpd7210 of NEC and TMS9914A of TI in software.NAT9914 mainly severs in programmable instrument with microprocessor, whose transform rate is 500kbps.The GPIB interface panel designed in this paper contains microprocessor(89c51) to special control this interface chip in order not to influence the ability of instrument. There are 25 register which include only-read and only-write type. Only-read register is used to save the message transferred from GPIB mother line and the status where is nat9914 interface function; only-write register is used to control work of nat9914 and transfer message to GPIB. Every kind of register has different function.NAT9914 is fulfilled by read or write operation carried out by microprocessor 89c51. The GPIB interface panel designed in this paper contains AT89C51,...