LPC47N227TQFP Standard Microsystems (SMSC), LPC47N227TQFP Datasheet - Page 62

• Manufacturer Part Number: LPC47N227TQFP
• Manufacturer: Standard Microsystems (SMSC)

Specifications of LPC47N227TQFP

• Lead Free Status / RoHS Status: Not Compliant

4) Issue Read/Write command.
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. Upon entering the Result Phase of:
2. End of Seek, Relative Seek, or Recalibrate command
3. FDC requires a data transfer during the execution phase in the non-DMA mode
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.
Sense Drive Status
Sense Drive Status obtains drive status information. It has not execution phase and goes directly to the
result phase from the command phase. Status Register 3 contains the drive status information.
Specify
The Specify command sets the initial values for each of the three internal times. The HUT (Head
Unload Time) defines the time from the end of the execution phase of one of the read/write commands
to the head unload state. The SRT (Step Rate Time) defines the time interval between adjacent step
a. Read Data command
b. Read A Track command
c. Read ID command
d. Read Deleted Data command
e. Write Data command
f.
g. Write Deleted Data command
h. Verify command
Format A Track command
SE
0
1
1
Table 25 - Interrupt Identification
11
00
01
IC
Polling
Normal termination of Seek or
Recalibrate command
Abnormal termination of Seek
or Recalibrate command
62
INTERRUPT DUE TO