PC8477BV-1 National Semiconductor, PC8477BV-1 Datasheet - Page 21

• Manufacturer Part Number: PC8477BV-1
• Description: IC ADVANCED FLOPPY CTRLR 68PLCC
• Manufacturer: National Semiconductor
• Series: SuperFDC™r

Specifications of PC8477BV-1

• Controller Type: Floppy Disk Controller
• Voltage - Supply: 4.5 V ~ 5.5 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 68-LCC (J-Lead)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Current - Supply: -
• Interface: -
• Other names: *PC8477BV-1

ure 4-1 shows the track format for the different formats rec-
4 0 Command Set Description
The Format command terminates when the index hole is
detected a second time at which point an interrupt is gener-
ated Only the first three status bytes in the Result Phase
are significant The Format Gap byte in the Command
Phase is dependent on the data rate and type of disk drive
and will control the length of GAP3 Some typical values for
the programmable GAP3 are given in Table 4-1 below Fig-
ognized by the Format Command
Note FM mode is not guaranteed through functional testing
Notes
Sector Gap refers to the Intersector Gap Length parameter specified in the Command Phase of the Read Write Scan and Verify commands Although this is the
recommended value the PC8477B treats this byte as a don’t care in the Read Write Scan and Verify commands
Format Gap is the suggested value to use in the Format Gap parameter of the Format command This is the programmable GAP3 as shown in Figure 4-1
The 2 88M diskette media is a new Barium Ferrite media intended for use in Perpendicular Recording drives at the data rate of up to 1 Mb s
125 kb s
FM
250 kb s
MFM
250 kb s
FM
500 kb s
MFM
Media
360K
1 2M
720K
1 44M
2 88M
Type
Mode
Decimal
Sector
Size
Decimal
512
512
512
512
512
Sector
1024
2048
1024
2048
4096
1024
2048
4096
1024
2048
4096
8192
Size
128
128
256
512
256
256
512
512
128
256
512
256
512
512
Typical Values for PC Compatible Diskette Media
TABLE 4-1 Typical Format Gap Length Values
Sector
(Continued)
Code
Hex
Sector
Code
02
02
02
02
02
Hex
00
00
01
02
03
04
01
01
02
02
03
04
05
00
01
02
03
04
05
01
02
02
03
04
05
06
21
4 2 4 Invalid Command
If an invalid command (illegal Opcode byte in the Command
Phase) is received by the controller the controller will re-
spond with ST0 in the Result Phase The controller does not
generate an interrupt during this condition Bits 6 and 7 in
the MSR are both set to a 1 indicating to the
controller is in the Result Phase and the contents of ST0
must be read The system will read an 80 (hex) value from
ST0 indicating an invalid command was received
EOT
Hex
09
0F
09
12
24
EOT
Hex
1A
0F
1A
0F
12
10
08
04
02
01
12
10
08
09
04
02
01
08
04
02
01
12
08
04
02
01
Sector
Sector
Gap
Hex
Gap
2A
1B
1B
1B
1B
Hex
C8
C8
C8
C8
C8
C8
C8
C8
07
10
18
46
0A
20
2A
2A
80
07
0E
1B
47
0E
1B
1B
35
99
Format
Format
GAP3
GAP
Hex
Hex
P that the
6C
50
54
50
53
FF
FF
0C
F0
FF
FF
1B
2A
3A
8A
FF
FF
6C
FF
FF
FF
09
19
30
87
32
50
50
36
54
74