FDC37C78-HT View Datasheet(PDF) - Microchip Technology

Part Name

Description

Manufacturer

FDC37C78-HT

Floppy Disk Controller

Microchip Technology 

CR02

This register can only be accessed in the Configuration Mode and after the CSR has been initialized

to 02H. The default value of this register after power up is 00H.

BIT NO.

0:7

BIT NAME

Reserved

Table 36 - CR02

DESCRIPTION

Read Only. A read returns a 0.

CR03

This register can only be accessed in the Configuration Mode and the CSR has been initialized

to 03H. The default value after power up is 70H.

BIT NO. BIT NAME

0 Reserved

1 Enhanced

Floppy Mode

2

2 Reserved

3 Reserved

4 DRVDEN1

5 MFM

6 IDENT

7 Reserved

Table 37 - CR03

DESCRIPTION

Reserved - Read as zero

Bit 1

Floppy Mode - Refer to the description of the TAPE

DRIVE REGISTER (TDR) for more information on these

modes.

0

NORMAL Floppy Mode (Default)

1

Enhanced Floppy Mode 2 (OS2)

Reserved - Read as zero

Reserved - Read as zero

0

DRVDEN 1 output as per DRVDEN table

1

DRVDEN 1 pin is tri-state (default)

IDENT is used in conjunction with MFM to define the interface mode of

operation.

IDENT

1

1

0

0

MFM

1

0

1

0

MODE

AT Mode (Default)

Reserved

Reserved

Reserved

Reserved - Read as zero

CR04

This register can only be accessed in the Configuration Mode and the CSR has been initialized

to 04H. The default value after power up is 00H.

BIT NO.

0:7

BIT NAME

Reserved

Table 38 - CR04

DESCRIPTION

Reserved - Read as zero

66

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