PC8477B Datasheet | National Semiconductor

Description The PC8477B CMOS advanced floppy disk controller is an enhanced version of National’s DP8473 floppy controller The PC8477B is software patible with the DP8473 and NEC m PD765 floppy disk controllers In addition it is pin and software patible with the Intel 82077AA floppy controller The PC8477B a 24 MHz crystal a device chip select and a resistor package are all that is needed for a plete PC-AT PS 2 or EISA floppy controller solution The PC8477B includes advanced features such as a 16 byte FIFO (Burst and Non-Burst modes) support of Perpendicular Recording Mode disk drives PS 2 diagnostic registers for Model 30 and Models 50 60 80 standard CMOS disk I O and additional mands to control these new features The 16 byte FIFO will increase system performance at higher data rates and with multi-tasking bus structures This controller is designed to fit into all PC-AT EISA and PS 2 designs as well as other advanced applications Features Pin and software patible with Intel 82077AA FDC Software patible with NSC’s DP8473 16 byte FIFO (default disabled) Burst and Non-Burst modes Programmable threshold Perpendicular Mode Recording drive support High performance internal analog data separator (no external filter ponents required) Low power CMOS with manual power down mode Automatic power down mode for plete software transparency Integrates all PC-AT and PS 2 logic On chip Oscillator PC patible FDC address decode PS 2 Model 30 and Model 50 60 80 diagnostic registers DMA control circuitry High current CMOS disk interface outputs Data Rate and Digital Output registers 12 m A m P bus interface buffers Data Rate Support 250 300 kb s 500 kb s and 1 Mb s Write prepensation software programmable 68 pin PLCC package 60 pin PQFP package Ideal for space limited applications Functional Block Diagram TL F 11332 - 3 FIGURE 1-1 Super FDCTM is a trademark of National Semiconductor Corporation TRI-STATE is a registered trademark of National Semiconductor...