CAT28F001 CATALYST [Catalyst Semiconductor], CAT28F001 Datasheet - Page 12

• Manufacturer Part Number: CAT28F001
• Description: 1 Megabit CMOS Boot Block Flash Memory
• Manufacturer: CATALYST [Catalyst Semiconductor]

CAT28F001
Figure 5 Block Erase Flowchart
Doc. No. 25071-00 2/98 F-1
FULL STATUS CHECK PROCEDURE
STATUS REGISTER DATA
CHECK IF DESIRED
READ (SEE ABOVE)
BLOCK ADDRESS
BLOCK ADDRESS
BLOCK ERASE
READ STATUS
BLOCK ERASE
SUCCESSFUL
FULL STATUS
COMPLETED
WRITE 20H,
WRITE D0H
REGISTER
SR.4,5 = 1?
SR.7 = 1?
SR.3 = 0?
SR.5 = 0?
START
YES
YES
NO
NO
YES COMMAND SEQUENCE
NO
NO
BLOCK ERASE
V
SUSPEND
PP
ERASE?
ERROR
ERROR
NO
ERROR
RANGE
ERASE SUSPEND
YES
LOOP
12
Repeat for subsequent blocks.
Full Status check can be done after each block or after a sequence
of blocks.
Write FFH after the last block erase operation to reset the device to
Read Array Mode.
SR.3 MUST be cleared, if set during a erase attempt, before further
attempts are allowed by the Write State Machine.
SR.3 is only cleared by the Clear Status Register Command, in
cases where multiple blocks are erased before full status is
checked.
If error is detected, clear the Status Register before attempting retry
or other error recovery.
Bus
Operation
Write
Write
Read
Standby
Bus
Operation
Standby
Standby
Standby
Command
Erase
Setup
Erase
Command
Comments
Data = 20H
Address = Within Block to be erased
Data - D0H
Address = Within Block to be erased
Status Register Data.
Toggle OE or CE to update
Status Register
Check SR.7
1 = Ready, 0 = Busy
Comments
Check SR.3
1 = V
Check SR.4
Both 1 = Command Sequence Error
Check SR.5
1 = Block Erase Error
PP
Low Detect