Dynamic Shift Registers - Bitsavers - Trailing-Edge

ROM Code ConvertersDM7598AA/DM8598AA TRI-STATETMsine table look-up read only memorygeneral descriptionThe DM7598AA/DM8598AA is a 256-bit bipolarread-only memory organized as 32 8-bit words.The 5-bit input code linearly divides 90° into 32equal segments. Each 8-bit output is therefore thesine of the angle applies.EXAMPLE: Input 11010 means 26/32 of 90°, orabout 73°. The corresponding output 11110100indicates (1/2 + 1/4 + 1/8 + 1/16 + 1/64) or about.95, which is close to the sine of 73°. Roundingoffhas not been employed, since without rounding-offIt is possible to extend the accuracy withadditional ROM's.The DM8598 is identical to the SN7488 exceptthat the Enable input on the SN7488 simply placesall outputs in the logical "·1" state, whereas theEnable input on the DM8598 places the outputsin a high impedance state. This high impedancestate allows many outputs to be connected inparallel for expansion to greater numbers of wordsand/or connection to a common bus line.features• Organized as 32 8-bit words• Party line capability• On-chip decoding• Pin compatible with SN7488• Typical access time 30 ns• Total power dissipation 350 mW• Compatible with Series 74 TTL and 930 DTL• Strobe input• I nput clamp diodesconnection diagramDual-In-Line Package14 13"1110GENABLEBINARY SELECTA,GENABLEOUTPUTS.....- Y1 OUTPUT YB 0 UTPUT I-- o NORMALOUTPUTSY2 Y3 Y4 Y5 Y6 Y7Hi-ZTOP VIEWtypical system connectionI 0M8598-TT II OM8598III OM8598~T~I~l~~II I I I I IIIII 11111222