DataSheet.es    


PDF DS2506 Data sheet ( Hoja de datos )

Número de pieza DS2506
Descripción 64-kbit Add-Only Memory
Fabricantes Dallas Semiconducotr 
Logotipo Dallas Semiconducotr Logotipo



Hay una vista previa y un enlace de descarga de DS2506 (archivo pdf) en la parte inferior de esta página.


Total 25 Páginas

No Preview Available ! DS2506 Hoja de datos, Descripción, Manual

www.dalsemi.com
FEATURES
65536 bits Electrically Programmable Read
Only Memory (EPROM) communicates with
the economy of one signal plus ground
Unique, factory-lasered and tested 64-bit
registration number (8-bit family code +
48-bit serial number + 8-bit CRC tester)
assures absolute traceability because no two
parts are alike
Built-in multidrop controller ensures
compatibility with other MicroLAN products
EPROM partitioned into two hundred fifty six
256-bit pages for randomly accessing
packetized data records
Each memory page can be permanently write-
protected to prevent tampering
Device is an “add only” memory where
additional data can be programmed into
EPROM without disturbing existing data
Architecture allows software to patch data by
superseding an old page in favor of a newly
programmed page
Reduces control, address, data, power, and
programming signals to a single data pin
Directly connects to a single port pin of a
microprocessor and communicates at up to
16.3 kbits per second
Overdrive mode boosts communication speed
to 142 kbits per second
8-bit family code specifies DS2506
communications requirements to reader
Presence detector acknowledges when the
reader first applies voltage
Low cost PR35 or 8-pin SOIC surface mount
package
Reads over a wide voltage range of 2.8V to
6.0V from -40°C to +85°C; programs at
11.5V to 12.0V from -40°C to +50°C
DS2506
64-kbit Add-Only Memory
PIN ASSIGNMENT
PR-35
DALLAS
DS2506
NC
NC
DATA
GND
18
27
36
45
8-PIN SOIC
(208 mil)
NC
NC
NC
NC
123
Bottom View
See Mech.
Drawings Section
ORDERING INFORMATION
DS2506
PR35 Package
DS2506S 8-Pin SOIC Package
1 of 25
062100

1 page




DS2506 pdf
DS2506
The next 32 bytes of the EPROM Status Memory (addresses 020 to 03FH) contain the Write Protect bits
which inhibit altering the Page Address Redirection Byte corresponding to each page in the 65536-bit
main memory area.
The following 32 bytes within the EPROM Status Memory (addresses 040 to 05FH) are reserved for use
by the iButton operating software TMEX. Their purpose is to indicate which memory pages are already in
use. Originally, all of these bits are unprogrammed, indicating that the device does not store any data. As
soon as data is written to any page of the device under control of TMEX, the bit inside this bitmap
corresponding to that page will be programmed to 0, marking this page as used. These bits are application
flags only and have no impact on the internal logic of the DS2506.
The next 256 bytes of the EPROM Status Memory (addresses 100H to 1FFH) contain the Page Address
Redirection Bytes which indicate if one or more of the pages of data in the 65536-bit EPROM section
have been invalidated by software and redirected to the page address contained in the appropriate
redirection byte. The hardware of the DS2506 makes no decisions based on the contents of the Page
Address Redirection Bytes. Since with EPROM technology bits can only be changed from a logical 1 to
a logical 0 by programming, it is not possible to simply rewrite a page if the data requires changing or
updating. But with space permitting, an entire page of data can be redirected to another page within the
DS2506. Under TMEX a page is redirected by writing the one’s complement of the new page address
into the Page Address Redirection Byte that corresponds to the original (replaced) page. This architecture
allows the user’s software to make a “data patch” to the EPROM by indicating that a particular page or
pages should be replaced with those indicated in the Page Address Redirection Bytes. To leave an
authentic audit trail of data patches, it is recommended to also program the write protect bit of the Page
Address Redirection Byte, after the page redirection is programmed. Without this protection, it is still
possible to modify the Page Address Redirection Byte, making it point to a different memory page than
the true one.
If a Page Address Redirection Byte has a FFH value, the data in the main memory that corresponds to
that page is valid. If a Page Address Redirection Byte has some other hex value than FFH, the data in the
page corresponding to that redirection byte is invalid. According to the TMEX definitions the valid data
can now be found at the one’s complement of the page address indicated by the hex value stored in the
associated Page Address Redirection Byte. A value of FDH in the redirection byte for page 1, for
example, would indicate that the updated data is now in page 2. The status memory is programmed
similarly to the data memory. Details for reading and programming the EPROM status memory portion of
the DS2506 are given in the Memory Function Commands section.
The Status Memory address range of the DS2506 extends from 000 to 1FFH. The memory locations 60H
to 0FFH and 200H and higher are physically not implemented. Reading these locations will usually
result in FFH bytes. Attempts to write to these locations will be ignored.
5 of 25

5 Page





DS2506 arduino
DS2506
After the 16-bit CRC of the last EPROM Status data page is read, the bus master will receive logical 1s
from the DS2506 until a Reset Pulse is issued. The Read Status command sequence can be ended at any
point by issuing a Reset Pulse.
EXTENDED READ MEMORY [A5H]
The Extended Read Memory command supports page redirection when reading data from the 65536-bit
EPROM data field. One major difference between the Extended Read Memory and the basic Read
Memory command is that the bus master receives the Redirection Byte first before investing time in
reading data from the addressed memory location. This allows the bus master to quickly decide whether
to continue and access the data at the selected starting page or to terminate and restart the reading process
at the redirected page address. A non-redirected page is identified by a Redirection Byte with a value of
FFH (see description of EPROM Status Bytes). If the Redirection Byte is different than this, the master
has to complement it to obtain the new page number. Multiplying the page number by 32 (20H) results in
the new address the master has to send to the DS2506 to read the updated data replacing the old data.
There is no logical limitation in the number of redirections of any page. The only limit is the number of
available memory pages within the DS2506.
In addition to page redirection, the Extended Read Memory command also supports “bit-oriented”
applications where the user cannot store a 16-bit CRC with the data itself. With bit-oriented applications
the EPROM information may change over time within a page boundary making it impossible to include
an accompanying CRC that will always be valid. Therefore, the Extended Read Memory command
concludes each page with the DS2506 generating and supplying a 16-bit CRC that is based on and
therefore always consistent with the current data stored in each page of the 65536-bit EPROM data field.
After having sent the command code of the Extended Read Memory command, the bus master follows
the command byte with a two byte address (TA1=(T7:T0), TA2=(T15:T8)) that indicates a starting byte
location within the data field. By sending eight read data time slots, the master receives the Redirection
Byte associated with the page given by the starting address. With the next sixteen read data time slots,
the bus master receives a 16-bit CRC of the command byte, address bytes and the Redirection Byte. This
CRC is computed by the DS2506 and read back by the bus master to check if the command word, starting
address and Redirection Byte were received correctly.
If the CRC read by the bus master is incorrect, a Reset Pulse must be issued and the entire sequence must
be repeated. If the CRC received by the bus master is correct, the bus master issues read time slots and
receives data from the DS2506 starting at the initial address and continuing until the end of a 32 byte
page is reached. At that point the bus master will send sixteen additional read time slots and receive a
16-bit CRC that is the result of shifting into the CRC generator all of the data bytes from the initial
starting byte to the last byte of the current page.
With the next 24 read data time slots the master will receive the Redirection Byte of the next page
followed by a 16-bit CRC of the Redirection Byte. After this, data is again read from the 65536-bit
EPROM data field starting at the beginning of the new page. This sequence will continue until the final
page and its accompanying CRC are read by the bus master. The Extended Read Memory command
provides a 16-bit CRC at two locations within the transaction flow chart: 1) after the Redirection Byte
and 2) at the end of each memory page. The CRC at the end of the memory page is always the result of
clearing the CRC generator and shifting in the data bytes beginning at the first addressed memory
location of the EPROM data page until the last byte of this page. With the initial pass through the
Extended Read Memory flow chart the 16-bit CRC value is the result of shifting the command byte into
the cleared CRC generator, followed by the two address bytes and the Redirection Byte. Subsequent
11 of 25

11 Page







PáginasTotal 25 Páginas
PDF Descargar[ Datasheet DS2506.PDF ]




Hoja de datos destacado

Número de piezaDescripciónFabricantes
DS25011A VERY LOW DROPOUT VOLTAGE REGULATORSAdvanced Monolithic Systems
Advanced Monolithic Systems
DS2501(DS2501 / DS2502) Add Only MemoryDallas Semiconductor
Dallas Semiconductor
DS25021 kbit Add-Only MemoryDallas Semiconducotr
Dallas Semiconducotr
DS2502DS2502Dallas Semiconducotr
Dallas Semiconducotr

Número de piezaDescripciónFabricantes
SLA6805M

High Voltage 3 phase Motor Driver IC.

Sanken
Sanken
SDC1742

12- and 14-Bit Hybrid Synchro / Resolver-to-Digital Converters.

Analog Devices
Analog Devices


DataSheet.es es una pagina web que funciona como un repositorio de manuales o hoja de datos de muchos de los productos más populares,
permitiéndote verlos en linea o descargarlos en PDF.


DataSheet.es    |   2020   |  Privacy Policy  |  Contacto  |  Buscar