Table 82 - DRVDEN1 Control
FDC OUTPUT
DRVDEN1
CONTROL
(CR05.1)
CONTROL
(CR03.4)
DRVDEN1
(PIN 18)
DESCRIPTION
0
0
1
0
1
X
1/0
1
TRISTATE
NORMAL DRVDEN1 FUNCTION
DRVDEN1 FORCED HIGH
ALL FDD OUTPUT PINS ARE
TRISTATED
CR06
CR06 can only be accessed in the configuration state and after the CSR has been initialized to 06H. The default
value of this register after power up is FFH (Table 83). CR06 holds the floppy disk drive type IDs for up to four floppy
disk drives (see section Drive Type ID, Bits 4 - 5 on page 23).
Table 83 - DR06: Drive Type ID Register
FDD3
FDD2
FDD1
FDD0
D7
D6
D5
D4
D3
D2
D1
D0
ID31
ID30
ID21
ID20
ID11
ID10
ID01
ID00
CR07
CR07 can only be accessed in the configuration state and after the CSR has been initialized to 07H. The default
value of this register after power up is 00H (Table 84). CR07 controls auto power management and the floppy boot
drive.
Table 84 - CR07: Auto Power Management and Boot Drive Select
BIT NO.
BIT NAME
DESCRIPTION
0,1
Floppy Boot
This bit is used to define the boot floppy.
0 = Drive A (default)
1 = Drive B
2
3
4
Reserved
Reserved
Read as 0.
Read as 0.
This bit controls the AUTOPOWER DOWN feature of the Parallel Port.
The function is:
0 = Auto powerdown disabled (default)
Parallel Port
Enable
1 = Auto powerdown enabled
This bit is reset to the default state by POR or a hardware reset.
This bit controls the AUTOPOWER DOWN feature of the UART2.
The function is:
0 = Auto powerdown disabled (default)
1 = Auto powerdown enabled
This bit is reset to the default state by POR or a hardware reset.
This bit controls the AUTOPOWER DOWN feature of the UART1.
The function is:
0 = Auto powerdown disabled (default)
1 = Auto powerdown enabled
5
6
7
UART 2 Enable
UART 1 Enable
This bit is reset to the default state by POR or a hardware reset.
This bit controls the AUTOPOWER DOWN feature of the Floppy Disk.
The function is:
Floppy Disk
Enable
0 = Auto powerdown disabled (default)
1 = Auto powerdown enabled
This bit is reset to the default state by POR or a hardware reset.
SMSC DS – FDC37N769
Page 102 of 137
Rev. 02-16-07
DATASHEET
SMSC [ SMSC CORPORATION ]
