ISSUE 4.7 : NOVEMBER 1998
MFM8516 - 70/90/12/15
Erase Suspend
Erase suspend allows the user to interrupt a Sector Erase operation and then perform data reads or programs
to a sector not being erased. This command is only applicable during the Sector Erase operation which in-
cludes the time-out period for sector erase. The Erase Suspend command will be ignored if written during Chip
Erase operation or Embedded Program Algorithm. Writing the Erase Suspend command during the Sector
Erase time-out results in immediate termination of the time-out period and suspension of the erase operation.
Any other command written during the Erase Suspend mode will be ignored except the Erase Resume
command. Writing the Erase Resume command resumes the erase operation. The addresses are "don't-
cares" when writing the Erase Suspend or Erase Resume command.
When the Erase Suspend command is written during the Sector Erase operation, the device will take a
maximum of 15µs to suspend the erase operation. When the device has entered the erase-suspend mode, D7
bit will be a logic '1', and D6 will stop toggling. The user must use the address of the erasing sector for reading
D6 and D7 to determine if the erase operation has been suspended. Further writes of the Erase Suspend
command are ignored.
When the erase operation has been suspended, the device defaults to the erase-suspend-read mode. Read-
ing data in this mode is the same as reading from the standard read mode except that the data must be read
from sectors that have not been erase-suspended. Successively reading from the erase-suspend sector while
the device is in the erase-suspend-read mode will cause D2 to toggle.
After entering the erase-suspend-read mode, the user can program the device by writing the appropriate
command sequence for Byte Program. This program mode is known as the erase-suspend-program mode.
Again, programming in this mode is the same as programming in the regular Byte Program mode except that
the data must be programmed to sectors that are not erase-suspended. Successively reading from the erase-
suspended sector while the device is in the erase-suspend-program mode will cause D2 to toggle. The end of
the erase-suspend-program operation is detected by Data Polling of D7, or by the Toggle bit (D6) which is the
same as the regular Byte Program operation. Note that D7 must be read from the byte program address while
D6 can be read from any address.
To resume the operation of Sector Erase, the Resume command should be written. Any further writes of the
Resume command at this point will be ignored. Another Erase Suspend command can be written after the chip
has resumed erasing.
WRITE OPERATIONS STATUS
Status
D7
D7
0
D6
D5
D3
In Progress
Byte Programming in Embedded Algorithm
Embedded Erase Algorithm
Toggle
Toggle
No Tog
Data
0
0
0
1
Erase
Erase Suspended Sector
1
0
1
Suspended Mode
Non-Erase Suspended Sector
Data
D7
0
Data
1
Data
0
Exceeded
Byte-Programming in Embedded Algorithm
Embedded Erase Algorithm
Toggle
Toggle
Toggle
Time Limits
1
1
Program in Erase Suspended Mode
D7
1
1
18
MOSAIC [ MOSAIC ]
