LPC47N227-MN View Datasheet(PDF) - SMSC -> Microchip
Part Name
Description
MFG CO.
'LPC47N227-MN' PDF : 202 Pages View PDF
FIFO THRESHOLD
EXAMPLES
1 byte
2 bytes
8 bytes
15 bytes
MAXIMUM DELAY TO SERVICING AT
500 Kbps DATA RATE
1 x 16 µs - 1.5 µs = 14.5 µs
2 x 16 µs - 1.5 µs = 30.5 µs
8 x 16 µs - 1.5 µs = 126.5 µs
15 x 16 µs - 1.5 µs = 238.5 µs
Digital Input Register (DIR)
Address 3F7 READ ONLY
This register is read-only in all modes.
PC-AT Mode
7
6
5
4
3
2
1
0
DSK
0
0
0
0
0
0
0
CHG
RESET N/A N/A N/A N/A N/A N/A N/A N/A
COND.
BIT 0 - 6 UNDEFINED
The data bus outputs D0 - 6 are read as ‘0’.
BIT 7 DSKCHG
This bit monitors the pin of the same name and reflects the opposite value seen on the disk cable or the
value programmed in the Force FDD Status Change Register (CR17). See the Configuration section for
register description.
PS/2 Mode
7
6
5
4
3
2
1
0
DSK
1
1
1
1 DRATE DRATE nHIGH
CHG
SEL1 SEL0 nDENS
RESET N/A N/A N/A N/A N/A N/A N/A
1
COND.
BIT 0 nHIGH DENS
This bit is low whenever the 500 Kbps or 1 Mbps data rates are selected, and high when 250 Kbps and 300
Kbps are selected.
BITS 1 - 2 DATA RATE SELECT
These bits control the data rate of the floppy controller. See Table 8 for the settings corresponding to the
individual data rates. The data rate select bits are unaffected by a software reset, and are set to 250
Kbps after a hardware reset.
BITS 3 - 6 UNDEFINED
Always read as a logic "1"
32
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