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参数资料
| 型号： | AT49F040T-90PI |
| 厂商： | ATMEL CORP |
| 元件分类： | DRAM |
| 英文描述： | 4-Megabit 512K x 8 5-volt Only CMOS Flash Memory |
| 中文描述： | 512K X 8 FLASH 5V PROM, 90 ns, PDIP32 |
| 封装： | 0.600 INCH, PLASTIC, DIP-32 |
| 文件页数： | 3/12页 |
| 文件大小： | 229K |
| 代理商： | AT49F040T-90PI |
AT49F040/040T
3
boot block is 00000H to 03FFFH while the address range
of the AT49F040T boot block is 7C000H to 7FFFFH.
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.
DATA POLLING:
The AT49F040 features DATA polling to
indicate the end of a program cycle. During a program
cycle an attempted read of the last byte loaded will result in
the complement of the loaded data on I/O7. Once the pro-
gram 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 AT49F040
provides another method for determining the end of a pro-
gram 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 toggling 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 AT49F040 in
the following ways: (a) V
CC
sense: if V
CC
is below 3.8V (typ-
ical), the program function is inhibited. (b) Program inhibit:
holding any one of OE low, CE high or WE high inhibits
program cycles. (c) Noise filter: pulses of less than 15 ns
(typical) on the WE or CE inputs will not initiate a program
cycle.
相关PDF资料 |
PDF描述 |
|---|---|
| AT49F040T-90TC | 4-Megabit 512K x 8 5-volt Only CMOS Flash Memory |
| AT49F040T-90TI | 4-Megabit 512K x 8 5-volt Only CMOS Flash Memory |
| AT49F040 | 4 Megabit 512K x 8 5-volt Only CMOS Flash Memory |
| AT49F040-12TC | 4-Megabit 512K x 8 5-volt Only CMOS Flash Memory |
| AT49F040-12TI | 4-Megabit 512K x 8 5-volt Only CMOS Flash Memory |
相关代理商/技术参数 |
参数描述 |
|---|---|
| AT49F040T-90TC | 制造商:ATMEL 制造商全称:ATMEL Corporation 功能描述:4-Megabit 512K x 8 5-volt Only CMOS Flash Memory |
| AT49F040T-90TI | 制造商:ATMEL 制造商全称:ATMEL Corporation 功能描述:4-Megabit 512K x 8 5-volt Only CMOS Flash Memory |
| AT49F080 | 制造商:ATMEL 制造商全称:ATMEL Corporation 功能描述:8-Megabit 1M x 8 5-volt Only Flash Memory |
| AT49F080-12CC | 制造商:ATMEL 制造商全称:ATMEL Corporation 功能描述:8-Megabit 1M x 8 5-volt Only Flash Memory |
| AT49F080-12CI | 制造商:ATMEL 制造商全称:ATMEL Corporation 功能描述:8-Megabit 1M x 8 5-volt Only Flash Memory |
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