FDC37C665IR SMSC Corporation, FDC37C665IR Datasheet - Page 68

• Manufacturer Part Number: FDC37C665IR
• Description: 3/5 Volt Advanced High-Performance Multi-Mode Parallel Port Super I/O Floppy Disk Controller with Infranred Support
• Manufacturer: SMSC Corporation

The values change with the data rate speed
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. In DMA mode, data
transfers are signalled 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
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
of
00
01
02
7F
7F
E
F
0
1
..
..
the
2M
64
56
60
4
..
63.5
FDC
2M
0.5
64
63
1
..
128
112
120
1M
8
..
meet
500K
Table 30 - Drive Control Delays (ms)
256
224
240
16
..
the
A Configure
HUT
128
126
127
1M
1
2
..
300K
26.7
426
373
400
..
system
250K
512
448
480
32
..
68
500K
256
252
254
2
4
..
selection and are documented in Table 30. The
values are the same for MFM and FM.
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.
programmable from 1 to 16 bytes. Defaults to
one byte. A "00" selects one byte; "0F" selects
16 bytes.
3.75
0.25
2M
0.5
..
4
HLT
1M
7.5
0.5
8
..
1
300K
426
420
423
3.3
6.7
..
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
This is