Programmierbare Ablaufsteuerung einer Plattensteuerung und ein Verfahren für eine zugehörige Kartenzuweisung

摘要

A programmable control sequencer for a magnetic disk drive storage system is described. The sequencer includes a random access memory (RAM) 36 containing a sequencer allocation map comprising a branch/data selection field and an encoded next address/count field as shown in figure 7. A branch/data selection decoder 46 decodes the information in the branch/data selection field, selecting a given data register to compare data read out from a disk with data of the selected data register and storing the compared data, the branch/data selection decoder generating a Read/Write signal to control operation of the disk and a sector updating signal. An address generator 38 generates an address for accessing the RAM by way of the information in the branch/data selection field and the encoded next address/count field. An address/count decoder 40 decodes the encoded next address/count value. A constant density recording (CDR) counter 42 counts a CDR split value from the branch/data selection decoder. A timer 44 counts operations according to a branch condition in the branch field and limits the maximum number of operations to the value in the count field. A sector updating circuit 50 executes a sector update responsive to the output of the branch/data selection decoder 46.