FDC37B72X_07 SMSC [SMSC Corporation], FDC37B72X_07 Datasheet - Page 64

• Manufacturer Part Number: FDC37B72X_07
• Description: 128 Pin Enhanced Super I/O Controller with ACPI Support
• Manufacturer: SMSC [SMSC Corporation]

The choice of DMA or non-DMA operations is
made by the ND bit. When this bit is "1", the non-
DMA mode is selected, and when ND is "0", the
DMA mode is selected.
transfers are signaled by the FDRQ pin. Non-DMA
mode uses the RQM bit and the FINT pin to signal
data transfers.
Configure
The Configure command is issued to select the
special features of the FDC.
command need not be issued if the default values
of the FDC meet the system requirements.
Configure Default Values:
EIS - No Implied Seeks
EFIFO - FIFO Disabled
POLL - Polling Enabled
FIFOTHR - FIFO Threshold Set to 1 Byte
PRETRK - Pre-Compensation Set to Track 0
7F
7F
00
01
02
E
0
1
..
F
..
2M
64
56
60
4
..
63.5
2M
0.5
64
63
1
..
128
112
120
1M
8
..
In DMA mode, data
500K
256
224
240
16
..
HUT
A Configure
128
126
127
1M
1
2
..
300K
26.7
426
373
400
..
250K
512
448
480
32
..
11
500K
256
252
254
2
4
..
EIS - Enable Implied Seek. When set to "1", the
FDC will perform a Seek operation before
executing a read or write command. Defaults to
no implied seek.
EFIFO - A "1" disables the FIFO (default). This
means data transfers are asked for on a byte-by-
byte basis. Defaults to "1", FIFO disabled. The
threshold defaults to "1".
POLL - Disable polling of the drives. Defaults to
"0", polling enabled.
interrupt is generated after a reset. No polling is
performed while the drive head is loaded and the
head unload delay has not expired.
FIFOTHR - The FIFO threshold in the execution
phase of read or write commands. This is
programmable from 1 to 16 bytes. Defaults to one
byte. A "00" selects one byte; "0F" selects 16
bytes.
PRETRK
Number.
Defaults to track 0. A "00" selects track 0; "FF"
selects track 255.
Version
The Version command checks to see if the
controller is an enhanced type or the older type
(765A). A value of 90 H is returned as the result
byte.
3.75
0.25
2M
0.5
4
..
HLT
1M
7.5
0.5
Programmable from track 0 to 255.
8
..
1
-
300K
426
420
423
3.3
6.7
Pre-Compensation
..
500K
16
15
..
2
1
SRT
When enabled, a single
300K
26.7
3.33
1.67
25
..
250K
512
504
508
4
8
.
250K
32
30
..
4
2
Start
Track