W83977AF Information Storage Devices, Inc, W83977AF Datasheet - Page 53

• Manufacturer Part Number: W83977AF
• Description: W83877TF Plus Kbc, Cir, RTC
• Manufacturer: Information Storage Devices, Inc

2.2.9 Configuration Control Register (CC Register) (Write base address + 7)
This register is used to control the data rate. In the PC/AT and PS/2 mode, the bit definitions are as
follows:
Bit 7-2: Reserved. These bits should be set to 0.
DRATE1 DRATE0 (Bit 1, 0):
These two bits select the data rate of the FDC.
In the PS/2 Model 30 mode, the bit definitions are as follows:
Bit 7-3: Reserved. These bits should be set to 0.
NOPREC (Bit 2):
This bit indicates no precompensation. It has no function and can be set by software.
DRATE1 DRATE0 (Bit 1, 0):
These two bits select the data rate of the FDC.
x
7
X: Reserved
X
X
7
:
x
6
Reserved
X
6
x
5
5
X
x
X
4
4
X
3
x
3
2
x
2
1
1
0
W83977F/ W83977AF
0
DRATE0
Publication Release Date: March 1998
DRATE1
NOPREC
DRATE0
DRATE1
-42-
PRELIMINARY
Revision 0.58