Electronic Components Datasheet Search |
|
7280L12PAIG8 Datasheet(PDF) 4 Page - Integrated Device Technology |
|
7280L12PAIG8 Datasheet(HTML) 4 Page - Integrated Device Technology |
4 / 12 page 4 COMMERCIALTEMPERATURERANGE IDT7280/7281/7282/7283/7284/7285 5V ASYNCHRONOUS FIFO DUAL 256 x 9, 512 x 9, 1,024 x 9, 2,048 x 9, 4,096 x 9 and 8,192 x 9 JUNE 29, 2012 SIGNAL DESCRIPTIONS INPUTS: DATA IN (D0 – D8) Data inputs for 9-bit wide data. CONTROLS: RESET (RS) ResetisaccomplishedwhenevertheReset(RS)inputistakentoaLOWstate. During reset, both internal read and write pointers are set to the first location. Aresetisrequiredafterpowerupbeforeawriteoperationcantakeplace.Both the Read Enable (R) and Write Enable (W) inputs must be in the HIGH state during the window shown in Figure 2, (i.e., tRSS before the rising edge of RS) and should not change until tRSR after the rising edge of RS. Half-Full Flag (HF) will be reset to HIGH after Reset (RS). WRITE ENABLE (W) A write cycle is initiated on the falling edge of this input if the Full Flag (FF) isnotset.Dataset-upandholdtimesmustbeadheredtowithrespecttotherising edgeoftheWriteEnable(W).DataisstoredintheRAMarraysequentiallyand independently of any on-going read operation. After half of the memory is filled and at the falling edge of the next write operation,theHalf-FullFlag(HF)willbesettoLOWandwillremainsetuntilthe difference between the write pointer and read pointer is less than or equal to onehalfofthetotalmemoryofthedevice.TheHalf-FullFlag(HF)isthenreset by the rising edge of the read operation. Topreventdataoverflow,theFullFlag(FF)willgoLOW,inhibitingfurther write operations. Upon the completion of a valid read operation, the Full Flag (FF) will go HIGH after tRFF, allowing a valid write to begin. When the FIFO is full, the internal write pointer is blocked from W, so external changes in Wwill notaffecttheFIFOwhenitisfull. READ ENABLE (R) AreadcycleisinitiatedonthefallingedgeoftheReadEnable(R)provided theEmptyFlag(EF)isnotset.ThedataisaccessedonaFirst-In/First-Outbasis, independent of any ongoing write operations. After Read Enable (R) goes HIGH,theDataOutputs(Q0–Q8)willreturntoahighimpedanceconditionuntil thenextReadoperation.WhenalldatahasbeenreadfromtheFIFO,theEmpty Flag (EF) will go LOW, allowing the “final” read cycle but inhibiting further read operations with the data outputs remaining in a high impedance state. Once a valid write operation has been accomplished, the Empty Flag (EF)willgoHIGH aftertWEFandavalidReadcanthenbegin.WhentheFIFOisempty,theinternal read pointer is blocked from Rso external changes in Rwill not affect the FIFO when it is empty. FIRST LOAD/RETRANSMIT (FL/RT) This is a dual-purpose input. In the Depth Expansion Mode, this pin is groundedtoindicatethatitisthefirstloaded(seeOperatingModes). IntheSingle DeviceMode,thispinactsastheretransmitinput.TheSingleDeviceModeis initiated by grounding the Expansion In (XI). ThesedevicescanbemadetoretransmitdatawhentheRetransmitEnable control(RT)inputispulsedLOW. Aretransmitoperationwillsettheinternalread pointertothefirstlocationandwillnotaffectthewritepointer.ReadEnable(R) andWriteEnable(W)mustbeintheHIGHstateduringretransmit.Thisfeature is useful when less than 256/512/1,024/2,048/4,096/8,192 writes are per- formedbetweenresets.TheretransmitfeatureisnotcompatiblewiththeDepth Expansion Mode and will affect the Half-Full Flag (HF), depending on the relative locations of the read and write pointers. EXPANSION IN (XI) Thisinputisadual-purposepin. ExpansionIn(XI)isgroundedtoindicate an operation in the single device mode. Expansion In (XI) is connected to Expansion Out (XO) of the previous device in the Depth Expansion or Daisy Chain Mode. OUTPUTS: FULL FLAG (FF) TheFullFlag(FF)willgoLOW,inhibitingfurtherwriteoperation,whenthe write pointer is one location less than the read pointer, indicating that the deviceisfull.IfthereadpointerisnotmovedafterReset(RS),theFull-Flag(FF) will go LOW after 256 writes for IDT7280, 512 writes for the IDT7281, 1,024 writes for the IDT7282, 2,048 writes for the IDT7283, 4,096 writes for the IDT7284 and 8,192 writes for the IDT7285. EMPTY FLAG (EF) TheEmptyFlag(EF)willgoLOW,inhibitingfurtherreadoperations,when the read pointer is equal to the write pointer, indicating that the device is empty. EXPANSION OUT/HALF-FULL FLAG (XO/HF) This is a dual-purpose output. In the single device mode, when Expan- sionIn(XI)isgrounded,thisoutputactsasanindicationofahalf-fullmemory. After half of the memory is filled and at the falling edge of the next write operation,theHalf-FullFlag(HF)willbesetLOWandwillremainsetuntilthe difference between the write pointer and read pointer is less than or equal toonehalfofthetotalmemoryofthedevice.TheHalf-FullFlag(HF)isthenreset by using rising edge of the read operation. IntheDepthExpansionMode,ExpansionIn(XI)isconnectedtoExpansion Out(XO)ofthepreviousdevice.Thisoutputactsasasignaltothenextdevice in the Daisy Chain by providing a pulse to the next device when the previous devicereachesthelastlocationofmemory. DATA OUTPUTS (Q0 – Q8) Data outputs for 9-bit wide data. This data is in a high impedance condition whenever Read (R) is in a HIGH state. |
Similar Part No. - 7280L12PAIG8 |
|
Similar Description - 7280L12PAIG8 |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.NET |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |