Rainbow-electronics DS1985 Manual do Utilizador

1 of 25 090299SPECIAL FEATURES§ 16384 bits Electrically Programmable ReadOnly Memory (EPROM) communicates withthe economy of one signal plus groun

DS198510 of 25MEMORY FUNCTION FLOW CHART (cont’d) Figure 5

DS198511 of 25MEMORY FUNCTION FLOW CHART (cont’d) Figure 5

DS198512 of 25EXTENDED READ MEMORY [A5H]The Extended Read Memory command supports page redirection when reading data from the 16384-bitEPROM data fie

DS198513 of 25WRITE MEMORY [0FH]The Write Memory command is used to program the 16384–bit EPROM data field. The bus master willfollow the command byt

DS198514 of 25For both of these cases, the decision to continue (to apply a Program Pulse to the DS1985) is madeentirely by the bus master, since the

DS198515 of 25As the DS1985 receives this byte of data into the scratchpad, it also shifts the data into the CRC generatorthat has been preloaded wit

DS198516 of 25The bus master requires a pullup resistor at the master end of the bus, with the bus master circuitequivalent to the one shown in Figur

DS198517 of 25DS1985 EQUIVALENT CIRCUIT Figure 6BUS MASTER CIRCUIT Figure 7TO DATA CONNECTIONOF DS2505CAPACITOR ADDED TO REDUCECOUPLING ON DATA LINE

DS198518 of 25ROM FUNCTIONS FLOW CHART Figure 8( See Figure 5 )

DS198519 of 25Match ROM [55H]The Match ROM command, followed by a 64-bit ROM sequence, allows the bus master to address aspecific DS1985 on a multidr

DS19852 of 25ORDERING INFORMATIONDS1985-F3 F3 MicroCanDS1985-F5 F5 MicroCanEXAMPLES OF ACCESSORIESDS9096P Self-Stick Adhesive PadDS9101 Multi-Pur

DS198520 of 25(Figure 11) should be applied for 480 µs, after which the bus master returns the data line to an idle highstate controlled by the pullu

DS198521 of 25READ/WRITE TIMING DIAGRAM (cont’d) Figure 10Write-0 Time Slot60 µs ≤ tLOW0 < tSLOT < 120 µs1 µs ≤ tREC < ∞Read-Data Time Slot6

DS198522 of 25PROGRAM PULSE TIMING DIAGRAM Figure 11CRC GENERATIONWith the DS1985 there are two different types of CRCs (Cyclic Redundancy Checks). O

DS198523 of 25When reading the data memory of the DS1985 with the Extended Read Memory command, there are twosituations where a 16-bit CRC is transmi

DS198524 of 25ABSOLUTE MAXIMUM RATINGS*Voltage on any Pin Relative to Ground -0.5V to +12.0VOperating Temperature -40°C to +85°CStorage Temperature

DS198525 of 25NOTES:1. All voltages are referenced to ground.2. VPUP = external pullup voltage. If VPUP is lower than 3.0V the first byte read (any

DS19853 of 25Figure 8. After a ROM Function Command is successfully executed, the memory functions that operateon the EPROM portions of the DS198

DS19854 of 25The 1-Wire CRC of the lasered ROM is generated using the polynomial X8 + X5 + X4 + 1. Additionalinformation about the Dallas Semiconduct

DS19855 of 2516384 BITS EPROMThe memory map in Figure 4 shows the 16384 bits EPROM section of the DS1985 which is configuredas 64 pages of 32 bytes e

DS19856 of 25If a Page Address Redirection Byte has a FFH value, the data in the main memory that corresponds to thatpage is valid. If a Page Address

DS19857 of 25The Status Memory address range of the DS1985 extends from 000 to 13FH. The memory locations008H to 01FH, 028H to 03FH, 048H to 0FFH and

DS19858 of 25READ STATUS [AAH]The Read Status command is used to read data from the EPROM Status data field. The bus masterfollows the command byte w

DS19859 of 25MEMORY FUNCTION FLOW CHART Figure 5