M29F032D70N1 STMICROELECTRONICS [STMicroelectronics], M29F032D70N1 Datasheet - Page 13

• Manufacturer Part Number: M29F032D70N1
• Description: 32 Mbit (4Mb x8, Uniform Block) 5V Supply Flash Memory
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

Table 4. Program, Erase Times and Program, Erase Endurance Cycles
Note: 1. T
STATUS REGISTER
Bus Read operations from any address always
read the Status Register during Program and
Erase operations. It is also read during Erase Sus-
pend when an address within a block being erased
is accessed.
The bits in the Status Register are summarized in
Table 5, Status Register Bits.
Data Polling Bit (DQ7). The Data Polling Bit can
be used to identify whether the Program/Erase
Controller has successfully completed its opera-
tion or if it has responded to an Erase Suspend.
The Data Polling Bit is output on DQ7 when the
Status Register is read.
During Program operations the Data Polling Bit
outputs the complement of the bit being pro-
grammed to DQ7. After successful completion of
the Program operation the memory returns to
Read mode and Bus Read operations from the ad-
dress just programmed output DQ7, not its com-
plement.
During Erase operations the Data Polling Bit out-
puts ’0’, the complement of the erased state of
DQ7. After successful completion of the Erase op-
eration the memory returns to Read Mode.
In Erase Suspend mode the Data Polling Bit will
output a ’1’ during a Bus Read operation within a
block being erased. The Data Polling Bit will
change from a ’0’ to a ’1’ when the Program/Erase
Controller has suspended the Erase operation.
Figure 5, Data Polling Flowchart, gives an exam-
ple of how to use the Data Polling Bit. A Valid Ad-
dress is the address being programmed or an
address within the block being erased.
Toggle Bit (DQ6). The Toggle Bit can be used to
identify whether the Program/Erase Controller has
successfully completed its operation or if it has re-
sponded to an Erase Suspend. The Toggle Bit is
output on DQ6 when the Status Register is read.
During Program and Erase operations the Toggle
Bit changes from ’0’ to ’1’ to ’0’, etc., with succes-
Chip Erase
Block Erase (64 Kbytes)
Program (Byte)
Chip Program (Byte by Byte)
Program/Erase Cycles (per Block)
A
= 25°C, V
Parameter
CC
= 5V.
100,000
Min
sive Bus Read operations at any address. After
successful completion of the operation the memo-
ry returns to Read mode.
During Erase Suspend mode the Toggle Bit will
output when addressing a cell within a block being
erased. The Toggle Bit will stop toggling when the
Program/Erase Controller has suspended the
Erase operation.
If any attempt is made to erase a protected block,
the operation is aborted, no error is signalled and
DQ6 toggles for approximately 100µs. If any at-
tempt is made to program a protected block or a
suspended block, the operation is aborted, no er-
ror is signalled and DQ6 toggles for approximately
1µs.
Figure 6, Data Toggle Flowchart, gives an exam-
ple of how to use the Data Toggle Bit.
Error Bit (DQ5). The Error Bit can be used to
identify errors detected by the Program/Erase
Controller. The Error Bit is set to ’1’ when a Pro-
gram, Block Erase or Chip Erase operation fails to
write the correct data to the memory. If the Error
Bit is set a Read/Reset command must be issued
before other commands are issued. The Error bit
is output on DQ5 when the Status Register is read.
Note that the Program command cannot change a
bit set to ’0’ back to ’1’ and attempting to do so will
set DQ5 to ‘1’. A Bus Read operation to that ad-
dress will show the bit is still ‘0’. One of the Erase
commands must be used to set all the bits in a
block or in the whole memory from ’0’ to ’1’.
Erase Timer Bit (DQ3). The Erase Timer Bit can
be used to identify the start of Program/Erase
Controller operation during a Block Erase com-
mand. Once the Program/Erase Controller starts
erasing the Erase Timer Bit is set to ’1’. Before the
Program/Erase Controller starts the Erase Timer
Bit is set to ’0’ and additional blocks to be erased
may be written to the Command Interface. The
Erase Timer Bit is output on DQ3 when the Status
Register is read.
Typ
0.8
40
10
40
(1)
100k W/E Cycles
Typical after
40
(1)
Max
200
200
200
6
M29F032D
cycles
Unit
µs
s
s
s
13/35