LPC47M172_07 SMSC [SMSC Corporation], LPC47M172_07 Datasheet - Page 69

• Manufacturer Part Number: LPC47M172_07
• Description: Advanced I/O Controller with Motherboard GLUE Logic
• Manufacturer: SMSC [SMSC Corporation]

6.19
SMSC/Non-SMSC Register Sets (Rev. 01-11-07)
Note that if implied seek is not enabled, the read and write commands should be preceded by:
1.
2.
3.
4.
The Seek command does not have a result phase. Therefore, it is highly recommended that the Sense
Interrupt Status command is issued after the Seek command to terminate it and to provide verification of
the head position (PCN). The H bit (Head Address) in ST0 will always return to a “0”. When exiting
POWERDOWN mode, the FDC clears the PCN value and the status information to zero. Prior to issuing
the POWERDOWN command, it is highly recommended that the user service all pending interrupts
through the Sense Interrupt Status command.
Sense Interrupt Status
An interrupt signal is generated by the FDC for one of the following reasons:
1.
2.
The Sense Interrupt Status command resets the interrupt signal and, via the IC code and SE bit of Status
Register 0, identifies the cause of the interrupt.
The Seek, Relative Seek, and Recalibrate commands have no result phase. The Sense Interrupt Status
command must be issued immediately after these commands to terminate them and to provide verification
of the head position (PCN). The H (Head Address) bit in ST0 will always return a “0”. If a Sense Interrupt
Status is not issued, the drive will continue to be BUSY and may affect the operation of the next command.
a. Read Data command
b. Read A Track command
c. Read ID command
d. Read Deleted Data command
e. Write Data command
f. Format A Track command
g. Write Deleted Data command
h. Verify command
Seek command - Step to the proper track
Sense Interrupt Status command - Terminate the Seek command
Read ID - Verify head is on proper track
Issue Read/Write command.
Upon entering the Result Phase of:
End of Seek, Relative Seek, or Recalibrate command
SE
0
1
1
Table 6.25 - Interrupt Identification
DATASHEET
11
00
01
IC
Polling
Normal termination of Seek
or Recalibrate command
Abnormal termination of
Seek or Recalibrate
command
Page 69
INTERRUPT DUE TO
Advanced I/O Controller with Motherboard GLUE Logic
SMSC LPC47M172
Datasheet