Programmable high performance disk formatter for headerless disk drive

Abstract

A programmable disk formatter for a disk controller in a headerless hard disk drive (HDD) system is disclosed. The disk formatter includes a high level processing engine that generates on the fly low level instructions that are executed by a low level processing engine. The disk formatter also includes a servo interface for interfacing the disk formatter to the servo timing logic, sector direct memory access (SDMA), and a QT/SP interface for interfacing the disk formatter to other processors in the disk controller, such as a system processor (SP) or Q-transmogrifier (QT) processor. The high level engine and low level engine operate semi-independently. The former processes SP- or QT-converted host computer commands in such a fashion that the low level instructions are generated and passed by the high level engine in time for the low level engine to execute them in coordination with the disk data rate. The high level engine is programmable with a high level instruction set, assembly language in the preferred embodiment, so that different drive formats can be accommodated with only software changes involving reprogramming of the high level engine and certain tracking/geometry tables stored in memory. The architecture and logic of the disk controller render a highly flexible, easily programmable. user friendly solution to the problem that disk controller designers face in accommodating each new generation of magnetic disks and each new approach to formatting.