M28W320 STMicroelectronics, M28W320 Datasheet - Page 11

• Manufacturer Part Number: M28W320
• Description: 32 Mbit 2Mb x16/ Boot Block Low Voltage Flash Memory
• Manufacturer: STMicroelectronics

Table 11. Protection States
Note: 1. All blocks are protected at power-up, so the default configuration is 001 or 101 according to WP status.
Table 12. Status Register Bits
Note: Logic level ’1’ is High, ’0’ is Low.
(WP, DQ1, DQ0)
Mnemonic
P/ECS
VPPS
ESS
PSS
BPS
2. Current state and Next state gives the protection status of a block. The protection status is defined by the write protect pin and by
3. Next state is the protection status of a block after a Protect or Unprotect or Lock command has been issued or after WP has changed
4. A WP transition to V
ES
PS
100
101
110
111
000
001
011
DQ1 (= 1 for a locked block) and DQ0 (= 1 for a protected block) as read in the Read Electronic Signature instruction with A1 = V
and A0 = V
its logic value.
Current State
Bit
7
6
5
4
3
2
1
0
IL
.
Program/Erase
P/E.C. Status
Erase
Suspend
Status
Erase Status
Program
Status
V
Program
Suspend
Status
Block
Protection
Status
Reserved
PP
Allowed
IH
(2)
Name
Status
on a locked block will restore the previous DQ0 value, giving a 111 or 110.
yes
yes
yes
no
no
no
no
(1)
Logic
Level
’1’
’0’
’1’
’0’
’1’
’0’
’1’
’0’
’1’
’0’
’1’
’0’
’1’
’0’
Protect
101
101
111
111
001
001
011
Ready
Busy
Suspended
In progress or
Completed
Erase Error
Erase Success
Program Error
Program Success
V
V
Suspended
In Progress or
Completed
Program/Erase on
protected Block,
Abort
No operation to
protected blocks
PP
PP
Definition
Invalid, Abort
OK
Unprotect
Next State After Event
100
100
110
110
000
000
011
Indicates the P/E.C. status, check during
Program or Erase, and on completion before
checking bits b4 or b5 for Program or Erase
Success.
On an Erase Suspend instruction P/ECS and
ESS bits are set to ’1’. ESS bit remains ’1’ until an
Erase Resume instruction is given.
ES bit is set to ’1’ if P/E.C. has applied the
maximum number of erase pulses to the block
without achieving an erase verify.
PS bit set to ’1’ if the P/E.C. has failed to program
a word.
V
when a Program or Erase instruction is executed.
V
erase/program operation.
On a Program Suspend instruction P/ECS and
PSS bits are set to ’1’. PSS remains ’1’ until a
Program Resume Instruction is given.
BPS bit is set to ’1’ if a Program or Erase
operation has been attempted on a protected
block.
PPS
PP
is sampled only at the beginning of the
bit is set if the V
M28W320CT, M28W320CB
Lock
111
111
111
111
011
011
011
(3)
PP
Note
voltage is below V
WP transition
111 or 110
000
001
011
011
100
101
PPLK
11/42
(4)
IH