FDC37C665GT(1994) Ver la hoja de datos (PDF) - SMSC -> Microchip

Número de pieza

componentes Descripción

fabricante

FDC37C665GT
(Rev.:1994)

High-Performance Multi-Mode Parallel Port Super I/O Floppy Disk Controllers

SMSC -> Microchip 

STATUS REGISTER B (SRB)

Address 3F1 READ ONLY

This register is read-only and monitors the state

of several disk interface pins, in PS/2 and Model

30 modes. The SRB can be accessed at any

time when in PS/2 mode. In the PC/AT mode

the data bus pins D0 - D7 are held in a high

impedance state for a read of address 3F1.

PS/2 Mode

7

1

RESET 1

COND.

6

5

4

3

2

1

0

1 DRIVE WDATA RDATA WGATE MOT MOT

SEL0 TOGGLE TOGGLE

EN1 EN0

1

0

0

0

0

0

0

BIT 0 MOTOR ENABLE 0

Active high status of the MTR0 disk interface

output pin. This bit is low after a hardware reset

and unaffected by a software reset.

BIT 1 MOTOR ENABLE 1

Active high status of the MTR1 disk interface

output pin. This bit is low after a hardware reset

and unaffected by a software reset.

BIT 2 WRITE GATE

Active high status of the WGATE disk interface

output.

BIT 3 READ DATA TOGGLE

Every inactive edge of the RDATA input causes

this bit to change state.

BIT 4 WRITE DATA TOGGLE

Every inactive edge of the WDATA input causes

this bit to change state.

BIT 5 DRIVE SELECT 0

Reflects the status of the Drive Select 0 bit of

the DOR (address 3F2 bit 0). This bit is cleared

after a hardware reset, it is unaffected by a

software reset.

BIT 6 RESERVED

Always read as a logic "1".

BIT 7 RESERVED

Always read as a logic "1".

26

Share Link: