HD63265 Floppy Disk Controller Users Manual 2ed Mar89 - Bitsavers

6.2.17 PCl, PCO: Precompensation Delay 1, 0D 7 D 6t-_ ______5P C 1_D_4___ D_ _. +1 ..._D 3 D 2______P C 0 _D_l___ D_0--lFigure 6-17. Precompensation Delay 1, 0PCl and PCO (figure 6-17) specify the amount of precompensation delays for theauto precompensation mode (table 6-6). PCO specifies the delay for the outertracks (smaller track numbers) and PCl specifies the delay for the inner tracks(larger track numbers). The FDC switches between PCO and PCl automaticallydepending on the head position. The switch-over track position is specifiedby PCDCT.Maximum programmable values for PCl and PCO are. HEX C in 5" mode. HEX 6 in 8" modeValues exceeding the above limits may cause malfunction.Table 6-6.Precompensation DelayPCl, PCOCLK=16 MHzDelay (ns)CLK=19.2 MHzHEX 0 0 0HEX 1 62.5 52.1HEX 2 125 104.2I I II I II I II I II I II I II I IHEX 6 375 312.5I I II I II I II I II I II I IHEX B 687.5 572.9HEX C 750 625HITACHI 27