pc8477b National Semiconductor Corporation, pc8477b Datasheet - Page 18

• Manufacturer Part Number: pc8477b
• Description: Advanced Floppy Disk Controller
• Manufacturer: National Semiconductor Corporation

4 0 Command Set Description
SET TRACK
Command Phase
Execution Phase Internal register is read or written
Result Phase
SPECIFY
Command Phase
Execution Phase Internal registers are written
No Result Phase
VERIFY
Command Phase
Execution Phase Data is read from disk but not transferred
to the system
Result Phase
VERSION
Command Phase
Result Phase
MT
0
0
EC
0
0
1
Step Rate Time
WNR
MFM
0
0
0
0
X
End of Track Sector Number
Data Length Sector Count
0
New Track Number (PTR)
Motor On Time
1
1
0
0
Intersector Gap Length
SK
X
Drive Head Number
Status Register 0
Status Register 1
Status Register 2
Bytes per Sector
Bytes per Sector
Sector Number
Sector Number
Track Number
Track Number
Head Number
0
1
0
1
1
1
X
Value
0
0
0
X
0
0
0
MSB
Motor Off Time
0
HD
0
1
0
0
DR1
DR1
1
0
1
0
0
(Continued)
DMA
DR0
DR0
1
1
0
0
0
18
WRITE DATA
Command Phase
Execution Phase Data is transferred from the system to
the controller via DMA or Non-DMA modes and written to
the disk
Result Phase
WRITE DELETED DATA
Command Phase
Execution Phase Data is transferred from the system to
the controller via DMA or Non-DMA modes and written to
the disk
Result Phase
MT
IPS
MT
IPS
MFM
MFM
X
X
End of Track Sector Number
End of Track Sector Number
Intersector Gap Length
Intersector Gap Length
X
X
0
0
Drive Head Number
Drive Head Number
Status Register 0
Status Register 1
Status Register 2
Status Register 0
Status Register 1
Status Register 2
Bytes per Sector
Bytes per Sector
Bytes per Sector
Bytes per Sector
Sector Number
Sector Number
Sector Number
Sector Number
Track Number
Track Number
Track Number
Track Number
Head Number
Head Number
Data Length
Data Length
X
X
0
0
0
X
1
X
HD
HD
1
0
DR1
DR1
0
0
DR0
DR0
1
1