Table 9 – Data Rates
DATA RATE DATA RATE
DRIVE RATE
DRATE(1)
DENSEL
DRT1
DRT0
SEL1
SEL0
MFM
FM
1
0
0
0
0
0
0
0
0
0
1
0
0
1
1
0
1
0
1Meg
500
300
---
1
1
0
0
1
0
0
1
1
0
1
0
250
150
125
250
0
0
0
0
1
1
1
1
1
0
0
1
1
0
1
0
1Meg
500
500
---
1
1
0
0
1
0
0
1
1
0
1
0
250
250
125
250
1
1
1
1
0
0
0
0
1
0
0
1
1
0
1
0
1Meg
500
2Meg
250
---
250
---
1
1
0
0
1
0
0
1
1
0
1
0
125
Drive Rate Table (Recommended) 00 = 360K, 1.2M, 720K, 1.44M and 2.88M Vertical Format
01 = 3-Mode Drive
10 = 2 Meg Tape
Note 1: The DRATE and DENSEL values are mapped onto the DRVDEN pins.
Table 10 – DRVDEN Mapping
DT1
0
DT0
0
DRVDEN1 (1)
DRVDEN0 (1)
DRIVE TYPE
4/2/1 MB 3.5"
2/1 MB 5.25" FDDS
DRATE0
DENSEL
2/1.6/1 MB 3.5" (3-MODE)
1
0
1
0
1
1
DRATE0
DRATE0
DRATE1
DRATE1
nDENSEL
DRATE0
PS/2
Table 11 – Default Precompensation Delays
PRECOMPENSATION
DATA RATE
DELAYS
2 Mbps
1 Mbps
20.8 ns
41.67 ns
125 ns
125 ns
125 ns
500 Kbps
300 Kbps
250 Kbps
SMSC DS – LPC47M14X
Page 33
Rev. 03/19/2001
SMSC [ SMSC CORPORATION ]
