ds2505pt-r Maxim Integrated Products, Inc., ds2505pt-r Datasheet
ds2505pt-r
Related parts for ds2505pt-r
ds2505pt-r Summary of contents
Page 1
FEATURES 16384 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 ...
Page 2
SILICON LABEL DESCRIPTION The DS2505 16-kbit Add–Only Memory identifies and stores relevant information about the product to which it is associated. This lot or product specific information can be accessed with minimal interface, for example a single port pin of ...
Page 3
This protocol is described in the ROM functions flow chart (Figure 8). The 1-Wire bus master must first provide one of four ROM function commands: 1) Read ROM, 2) Match ROM, 3) Search ROM ...
Page 4
HIERARCHICAL STRUCTURE FOR 1-WIRE PROTOCOL Figure 2 64-BIT LASERED ROM Figure 3 8-Bit CRC Code MSB 16384-BITS EPROM The memory map in Figure 4 shows the 16384-bit EPROM section of the DS2505 which is configured as 64 pages of 32 ...
Page 5
EPROM STATUS BYTES In addition to the 16384 bits of data memory the DS2505 provides 704 bits of Status Memory accessible with separate commands. The EPROM Status Bytes can be read or programmed to indicate various conditions to the software ...
Page 6
The Status Memory address range of the DS2505 extends from 000 to 13FH. The memory locations 008H to 01FH, 028H to 03FH, 048H to 0FFH and 140H to 7FFH are physically not implemented. Reading these locations will usually result in ...
Page 7
MEMORY FUNCTION COMMANDS The “Memory Function Flow Chart” (Figure 5) describes the protocols necessary for accessing the various data fields within the DS2505. The Memory Function Control section, 8-bit scratchpad, and the Program Voltage Detect circuit combine to interpret the ...
Page 8
MEMORY FUNCTION FLOW CHART Figure ...
Page 9
MEMORY FUNCTION FLOW CHART Figure 5 (cont’ ...
Page 10
MEMORY FUNCTION FLOW CHART Figure 5 (cont’ ...
Page 11
Note that the initial pass through the Read Status flow chart will generate a 16-bit CRC value that is the result of clearing the CRC generator and then shifting in the command byte followed by the 2 address bytes, and ...
Page 12
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 16,384-bit EPROM data field ...
Page 13
As the DS2505 receives this byte of data into the scratchpad, it also shifts the data into the CRC generator that has been preloaded with the current address and the result is a 16-bit CRC of the new data byte ...
Page 14
EPROM Status address sent least significant bit first. This byte contains the logical AND of all bytes written to this EPROM Status Byte address. If the EPROM Status Byte contains 1s in bit ...
Page 15
Hardware Configuration The 1-Wire bus has only a single line by definition important that each device on the bus be able to drive it at the appropriate time. To facilitate this, each device attached to the 1-Wire bus ...
Page 16
DS2505 EQUIVALENT CIRCUIT Figure 6 BUS MASTER CIRCUIT Figure ...
Page 17
ROM FUNCTIONS FLOW CHART Figure ...
Page 18
Match ROM [55H] The Match ROM command, followed by a 64-bit ROM sequence, allows the bus master to address a specific DS2505 on a multidrop bus. Only the DS2505 that exactly matches the 64-bit ROM sequence will respond to the ...
Page 19
Note that due to the high voltage programming requirements for any 1-Wire EPROM ...
Page 20
READ/WRITE TIMING DIAGRAM Figure 10 (cont’d) NOTE: For read-data time slots the optimal sampling point for the master is as close as possible to the end of the t period without exceeding the 15 µs window. For the case of ...
Page 21
PROGRAM PULSE TIMING DIAGRAM Figure 11 CRC GENERATION With the DS2505 there are two different types of CRCs (Cyclic Redundancy Checks). One CRC is an 8-bit type and is stored in the most significant byte of the 64-bit ROM. The ...
Page 22
When reading the data memory of the DS2505 with the Extended Read Memory command, there are two situations where a 16-bit CRC is transmitted. One 16-bit CRC follows each Redirection Byte; another 16-bit CRC is received after the last byte ...
Page 23
ABSOLUTE MAXIMUM RATINGS* Voltage on any Pin Relative to Ground Operating Temperature Storage Temperature Soldering Temperature * This is a stress rating only and functional operation of the device at these or any other conditions outside those indicated in the ...
Page 24
NOTES: 1. All voltages are referenced to ground external pullup voltage PUP may not reproduce the correct memory contents. Therefore, under low voltage conditions recommended to set either the most significant bit or ...