at49lw040 ATMEL Corporation, at49lw040 Datasheet - Page 16

• Manufacturer Part Number: at49lw040
• Description: At49lw040 4-megabit Firmware Hub Flash Memory
• Manufacturer: ATMEL Corporation

Status Register Definition
Notes:
16
B7
B5
B4
B3
B1
B0
1. Check B7 to determine sector erase or program completion. B6 - B0 are invalid while B7 = “0”.
2. If both B5 and B4 are “1”s after a sector erase attempt, an improper command sequence was entered.
3. B3 does not provide a continuous indication of V
4. B1 does not provide a continuous indication of Write Lock bit, TBL pin or WP pin values. The WSM interrogates the Write
5. B0 is reserved for future use and should be masked out when polling the status register.
6. B2 = B6 = 0.
AT49LW040
tor erase or program operation. B3 is not guaranteed to report accurate feedback only when V
Lock bit, TBL pin or WP pin only after a sector erase or program operation. Depending on the attempted operation, it informs
the system whether or not the selected sector is locked.
Write State Machine Status
Erase Status
Program Status
V
Device Protect Status
Reserved for Future Enhancements
PP
Status
(3)
(2)
(4)
After writing this command, all subsequent read operations will return data from the sta-
tus register until another valid command is written. The Read Status Register command
functions independently of the V
CLEAR STATUS REGISTER: Error flags in the status register can only be set to “1”s by
the WSM and can only be reset by the Clear Status Register command. These bits indi-
cate various failure conditions. The Clear Status Register command functions
independently of the applied V
(1)
(5)
PP
level. The WSM interrogates and indicates the V
1
0
1
0
1
0
1
0
1
0
Ready
Busy
Error in Sector Erasure
Successful Sector Erase
Error in Program
Successful Program
V
V
Write Lock Bit, TBL Pin or WP Pin Detected, Operation Abort
Unlock
PP
PP
PP
PP
voltage.
Low Detect, Operation Abort
OK
voltage.
PP
V
PP
PPH1
level only after a sec-
.
3342A–FLASH–6/03