memory products - Al Kossow's Bitsavers

M2732APROGRAMMING OPERATION (Continued)PROGRAMMING WAVEFORMSPROGRAMPROGRAMVERI FYADDRESSESDATA-~Yt--tDF (o.I3)maxVppOE/VppVILCEVIHVIL5- 670 1NOles: I. All times shown in ( ) are minimum and in psec unless otherwise specified.2. The input liming reference level is IV for VIL and 2V for VIH.3. tOE and tOF are characteristics of the device but must be accomodated by the programmer.PROGRAMMINGCaution: Exceeding 22V on pin (Vpp) will damagethe M2732A.When delivered, and after each erasure, all bits ofthe M2732A are in the "1" state. Data is introducedby selectively programming "D's" into the desiredbit locations. Although only "D's" will beprogrammed, both "1's" and "D's" can be presentedin the data word. The only way to change a "0"to a "1" is by ultraviolet light erasure.The M2732A is in the programming mode when theOElVpp input is at 21V. It is required that a 0.1 /tFcapacitor be placed across OElVpp and ground tosuppress spurious voltage transients which may damagethe device .. The data to be programmed isapplied 8 bits in parallel to the data output pins.The levels required for the address and data inputsare TIl.When the address and data are stable, a 50 ms~active low, TIL program pulse is applied to the CEinput. A program pulse must be applied at eachaddress location to be programmed. You can pro-gram any location at any time - either individually,sequentially, or at random. The program pulsehas a maximum width of 55 msec. The 2732A mustnot be programmed with a DC signal applied to theCE input.Programming of multiple 2732As in parallel withthe same data can be easily accomplished due tothe simplicity of the programming requirements. likeinputs of the paralleled M2732As may be connectedtogether when they are programmed withthe same data. A low level TIL pulse applied tothe CE input programs the paralleled 2732As.PROGRAM INHIBITProgramming of multiple 2732As in parallel withdifferent data is also easily accommLshed. Exceptfor CE, all like inputs (including OElVpp) of theparallel 2732As may be common. A TIL level pro-9.@m pulse applied to a 2732A's CE input withOE£Ypp at 21V will program that 2732A. A high levelCE input inhibits the other 2732As from beingprogrammed.6/740