To allow for simple in-system reprogrammability, the
AT49F010/HF010 does not require high input voltages for
programming. Five-volt-only commands determine the read
and programming operation of the device. Reading data
out of the device is similar to reading from an EPROM.
Reprogramming the AT49F010/HF010 is performed by
erasing the entire 1 megabit of memory and then program-
ming on a byte by byte basis. The byte programming time
is a fast 50
µs.
The end of a program cycle can be option-
ally detected by the DATA polling feature. Once the end of
a byte program cycle has been detected, a new access for
a read or program can begin. The typical number of pro-
gram and erase cycles is in excess of 10,000 cycles.
The optional 8K bytes boot block section includes a repro-
gramming write lock out feature to provide data integrity.
The boot sector is designed to contain user secure code,
and when the feature is enabled, the boot sector is perma-
nently protected from being reprogrammed.
Block Diagram
1FFFF
02000
01FFF
00000
Device Operation
READ:
The AT49F010/HF010 is accessed like an EPROM.
When CE and OE are low and WE is high, the data stored
at the memory location determined by the address pins is
asserted on the outputs. The outputs are put in the high
impedance state whenever CE or OE is high. This dual-line
control gives designers flexibility in preventing bus conten-
tion.
ERASURE:
Before a byte can be reprogrammed, the 128K
bytes memory array (or 120K bytes if the boot block fea-
tured is used) must be erased. The erased state of the
memory bits is a logical “1”. The entire device can be
erased at one time by using a 6-byte software code. The
chip erase code consists of 6-byte load commands to spe-
cific address locations with a specific data pattern (please
refer to the Chip Erase Cycle Waveforms).
After the chip erase has been initiated, the device will inter-
nally time the erase operation so that no external clocks
are required. The maximum time needed to erase the
whole chip is t
EC
. If the boot block lockout feature has been
enabled, the data in the boot sector will not be erased.
BYTE PROGRAMMING:
Once the memory array is
erased, the device is programmed (to a logical “0”) on a
byte-by-byte basis. Please note that a data “0” cannot be
programmed back to a “1”; only erase operations can con-
vert “0”s to “1”s. Programming is accomplished via the
internal device command register and is a 4 bus cycle
operation (please refer to the Command Definitions table).
The device will automatically generate the required internal
program pulses.
The program cycle has addresses latched on the falling
edge of WE or CE, whichever occurs last, and the data
latched on the rising edge of WE or CE, whichever occurs
first. Programming is completed after the specified t
BP
cycle
time. The DATA polling feature may also be used to indi-
cate the end of a program cycle.
BOOT BLOCK PROGRAMMING LOCKOUT:
The device
has one designated block that has a programming lockout
feature. This feature prevents programming of data in the
designated block once the feature has been enabled. The
size of the block is 8K bytes. This block, referred to as the
boot block, can contain secure code that is used to bring up
the system. Enabling the lockout feature will allow the boot
code to stay in the device while data in the rest of the
device is updated. This feature does not have to be acti-
vated; the boot block’s usage as a write protected region is
optional to the user. The address range of the boot block is
00000H to 01FFFH.
Once the feature is enabled, the data in the boot block can
no longer be erased or programmed. Data in the main
memory block can still be changed through the regular pro-
gramming method. To activate the lockout feature, a series
of six program commands to specific addresses with spe-
cific data must be performed. Please refer to the Command
Definitions table.
BOOT BLOCK LOCKOUT DETECTION:
A software
method is available to determine if programming of the boot
block section is locked out. When the device is in the soft-
ware product identification mode (see Software Product
Identification Entry and Exit sections) a read from address
location 00002H will show if programming the boot block is
locked out. If the data on I/O0 is low, the boot block can be
programmed; if the data on I/O0 is high, the program lock-
out feature has been activated and the block cannot be
programmed. The software product identification code
should be used to return to standard operation.
PRODUCT IDENTIFICATION:
The product identification
mode identifies the device and manufacturer as Atmel. It
may be accessed by hardware or software operation. The
hardware operation mode can be used by an external pro-
grammer to identify the correct programming algorithm for
the Atmel product.
For details, see Operating Modes (for hardware operation)
or Software Product Identification. The manufacturer and
device code is the same for both modes.
2
AT49HF/F010
AT49HF/F010
DATA POLLING:
The AT49F010/HF010 features DATA
polling to indicate the end of a program cycle. During a pro-
gram cycle an attempted read of the last byte loaded will
result in the complement of the loaded data on I/O7. Once
the program cycle has been completed, true data is valid
on all outputs and the next cycle may begin. DATA polling
may begin at any time during the program cycle.
TOGGLE BIT:
In addition to DATA polling the
AT49F010/HF010 provides another method for determining
the end of a program or erase cycle. During a program or
erase operation, successive attempts to read data from the
device will result in I/O6 toggling between one and zero.
Once the program cycle has completed, I/O6 will stop tog-
gling and valid data will be read. Examining the toggle bit
may begin at any time during a program cycle.
HARDWARE DATA PROTECTION:
Hardware features
protect against inadvertent programs to the
AT49F010/HF010 in the following ways: (a) V
CC
sense—if
V
CC
is below 3.8V (typical), the program function is inhib-
ited; (b) Program inhibit—holding any one of OE low, CE
high or WE high inhibits program cycles; and (c) Noise fil-
ter—Pulses of less than 15 ns (typical) on the WE or CE
inputs will not initiate a program cycle.
Command Definition (in Hex)
Command
Sequence
Bus
Cycles
1st Bus
Cycle
Addr
Read
Chip Erase
Byte
Program
Boot Block
Lockout
(1)
Product ID
Entry
Product ID
Exit
(2)
Product ID
Exit
(2)
Notes:
1
6
4
6
3
3
1
Addr
5555
5555
5555
5555
5555
XXXX
Data
D
OUT
AA
AA
AA
AA
AA
F0
2AAA
2AAA
2AAA
2AAA
2AAA
55
55
55
55
55
5555
5555
5555
5555
5555
80
A0
80
90
F0
5555
Addr
5555
AA
D
IN
AA
2AAA
55
5555
40
2AAA
55
5555
10
2nd Bus
Cycle
Addr
Data
3rd Bus
Cycle
Addr
Data
4th Bus
Cycle
Addr
Data
5th Bus
Cycle
Addr
Data
6th Bus
Cycle
Addr
Data
1. The 8K word boot sector has the address range 00000H to 01FFFH.
2. Either one of the Product ID exit commands can be used.
Absolute Maximum Ratings*
Temperature Under Bias ................................ -55°C to +125°C
Storage Temperature ..................................... -65°C to +150°C
All Input Voltages
(including NC Pins)
with Respect to Ground ...................................-0.6V to +6.25V
All Output Voltages
with Respect to Ground .............................-0.6V to V
CC
+ 0.6V
Voltage on OE
with Respect to Ground ...................................-0.6V to +13.5V
*NOTICE:
Stresses beyond those listed under “Absolute
Maximum Ratings” may cause permanent dam-
age to the device. This is a stress rating only and
functional operation of the device at these or any
other conditions beyond those indicated in the
operational sections of this specification is not
implied. Exposure to absolute maximum rating
conditions for extended periods may affect
device reliability.
3
Real-time operating system RTOS
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