Revised August 1999 74F433 First-In First-Out (FIFO) Buffer Memory General Description Features The 74F433 is an expandable fall-through type high-speed First-In First-Out (FIFO) Buffer Memory that is optimized for high-speed disk or tape controller and communication buffer applications. It is organized as 64-words by 4-bits and may be expanded to any number of words or any number of bits in multiples of four. Data may be entered or extracted asynchronously in serial or parallel, allowing economical implementation of buffer memories. ■ Serial or parallel input ■ Serial or parallel output ■ Expandable without additional logic ■ 3-STATE outputs ■ Fully compatible with all TTL families ■ Slim 24-pin package ■ 9423 replacement The 74F433 has 3-STATE outputs that provide added versatility, and is fully compatible with all TTL families. Ordering Code: Order Number Package Number 74F433SPC N24C Package Description 24-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-100, 0.300 Wide Logic Symbol © 1999 Fairchild Semiconductor Corporation Connection Diagram DS009544 www.fairchildsemi.com 74F433 First-In First-Out (FIFO) Buffer Memory April 1988 74F433 Unit Loading/Fan Out Pin Names U.L. Input IIH/IIL HIGH/LOW Output IOH/IOL Description PL Parallel Load Input 1.0/0.66 20 µA/400 µA CPSI Serial Input Clock 1.0/0.66 20 µA/400 µA IES Serial Input Enable 1.0/0.66 20 µA/400 µA TTS Transfer to Stack Input 1.0/0.66 20 µA/400 µA MR Master Reset 1.0/0.66 20 µA/400 µA OES Serial Output Enable 1.0/0.66 20 µA/400 µA TOP Transfer Out Parallel 1.0/0.66 20 µA/400 µA 20 µA/400 µA TOS Transfer Out Serial 1.0/0.66 CPSO Serial Output Clock 1.0/0.66 20 µA/400 µA OE Output Enable 1.0/0.66 20 µA/400 µA D0–D3 Parallel Data Inputs 1.0/0.66 20 µA/400 µA DS Serial Data Input 1.0/0.66 20 µA/400 µA Q0–Q3 Parallel Data Outputs 285/10 5.7 mA/16 mA QS Serial Data Output 285/10 5.7 µA/16 mA IRF Input Register Full 20/5 400 µA/8 mA ORE Output Register Empty 20/5 400 µA/8 mA Block Diagram www.fairchildsemi.com 2 As shown in the block diagram, the 74F433 consists of three sections: the last flip-flop (FC) is brought out as the Input Register Full (IRF) signal. After initialization, this output is HIGH. 1. An Input Register with parallel and serial data inputs, as well as control inputs and outputs for input handshaking and expansion. Parallel Entry—A HIGH on the Parallel Load (PL) input loads the D0–D3 inputs into the F0–F3 flip-flops and sets the FC flip-flop. This forces the IRF output LOW, indicating that the input register is full. During parallel entry, the Serial Input Clock (CPSI) input must be LOW. 2. A 4-bit-wide, 62-word-deep fall-through stack with selfcontained control logic. Serial Entry—Data on the Serial Data (DS) input is serially entered into the shift register (F3, F2, F1, F0, FC) on each HIGH-to-LOW transition of the CPSI input when the Serial Input Enable (IES) signal is LOW. During serial entry, the PL input should be LOW. 3. An Output Register with parallel and serial data outputs, as well as control inputs and outputs for output handshaking and expansion. These three sections operate asynchronously and are virtually independent of one another. After the fourth clock transition, the four data bits are located in flip-flops F0–F3. The FC flip-flop is set, forcing the IRF output LOW and internally inhibiting CPSI pulses from affecting the register. Figure 2 illustrates the final positions in an 74F433 resulting from a 256-bit serial bit train (B0 is the first bit, B255 the last). Input Register (Data Entry) The Input Register can receive data in either bit-serial or 4bit parallel form. It stores this data until it is sent to the fallthrough stack, and also generates the necessary status and control signals. This 5-bit register (see Figure 1) is initialized by setting flipflop F3 and resetting the other flip-flops. The Q-output of FIGURE 1. Conceptual Input Section 3 www.fairchildsemi.com 74F433 Functional Description 74F433 fer, ORE goes HIGH, indicating valid data on the data outputs (provided that the 3-STATE buffer is enabled). The TOP input can then be used to clock out the next word. When TOP goes LOW, ORE also goes LOW, indicating that the output data has been extracted; however, the data itself remains on the output bus until a HIGH level on TOP permits the transfer of the next word (if available) into the output register. During parallel data extraction, the serial output clock (CPSO) line should be LOW. The Transfer Out Serial (TOS) line should be grounded for single-slice operation or connected to the appropriate ORE line for expanded operation (refer to the “Expansion” section). The TOP signal is not edge-triggered. Therefore, if TOP goes HIGH before data is available from the stack but data becomes available before TOP again goes LOW, that data is transferred into the output register. However, internal control circuitry prevents the same data from being transferred twice. If TOP goes HIGH and returns to LOW before data is available from the stack, ORE remains LOW, indicating that there is no valid data at the outputs. FIGURE 2. Final Positions in an 74F433 Resulting from a 256-Bit Serial Train Fall-Through Stack—The outputs of flip-flops F0–F3 feed the stack. A LOW level on the Transfer to Stack (TTS) input initiates a fall-through action; if the top location of the stack is empty, data is loaded into the stack and the input register is re-initialized. (Note that this initialization is delayed until PL is LOW). Thus, automatic FIFO action is achieved by connecting the IRF output to the TTS input. Serial Extraction—When the FIFO is empty after a LOW is applied to the MR input, the ORE output is LOW. After data has been entered into the FIFO and has fallen through to the bottom stack location, it is transferred into the output register, if the TOS input is LOW and TOP is HIGH. As a result of the data transfer, ORE goes HIGH, indicating that valid data is in the register. The 3-STATE Serial Data Output (QS) is automatically enabled and puts the first data bit on the output bus. Data is serially shifted out on the HIGH-to-LOW transition of CPSO. To prevent false shifting, CPSO should be LOW when the new word is being loaded into the output register. The fourth transition empties the shift register, forces ORE LOW, and disables the serial output, QS. For serial operation, the ORE output may be tied to the TOS input, requesting a new word from the stack as soon as the previous one has been shifted out. An RS-type flip-flop (the initialization flip-flop) in the control section records the fact that data has been transferred to the stack. This prevents multiple entry of the same word into the stack even though IRF and TTS may still be LOW; the initialization flip-flop is not cleared until PL goes LOW. Once in the stack, data falls through automatically, pausing only when it is necessary to wait for an empty next location. In the 74F433, the master reset (MR) input only initializes the stack control section and does not clear the data. Output Register The Output Register (see Figure 3) receives 4-bit data words from the bottom stack location, stores them, and outputs data on a 3-STATE, 4-bit parallel data bus or on a 3STATE serial data bus. The output section generates and receives the necessary status and control signals. Expansion Vertical Expansion—The 74F433 may be vertically expanded, without external components, to store more words. The interconnections necessary to form a 190-word by 4-bit FIFO are shown in Figure 4. Using the same technique, any FIFO of (63n+1)-words by 4-bits can be configured, where n is the number of devices. Note that expansion does not sacrifice any of the 74F433 flexibility for serial/parallel input and output. Parallel Extraction—When the FIFO is empty after a LOW pulse is applied to the MR input, the Output Register Empty (ORE) output is LOW. After data has been entered into the FIFO and has fallen through to the bottom stack location, it is transferred into the output register, if the Transfer Out Parallel (TOP) input is HIGH. As a result of the data trans- www.fairchildsemi.com 4 74F433 FIGURE 3. Conceptual Output Section 5 www.fairchildsemi.com 74F433 FIGURE 4. A Vertical Expansion Scheme It should be noted that the horizontal expansion scheme shown in Figure 5 exacts a penalty in speed. Horizontal Expansion—The 74F433 can be horizontally expanded, without external logic, to store long words (in multiples of 4-bits). The interconnections necessary to form a 64-word by 12-bit FIFO are shown in Figure 5. Using the same technique, any FIFO of 64-words by 4n-bits can be constructed, where n is the number of devices. Horizontal and Vertical Expansion—The 74F433 can be expanded in both the horizontal and vertical directions without any external components and without sacrificing any of its FIFO flexibility for serial/parallel input and output. The interconnections necessary to form a 127-word by 16bit FIFO are shown in Figure 6. Using the same technique, any FIFO of (63m+1)-words by 4n-bits can be configured, where m is the number of devices in a column and n is the number of devices in a row. Figure 7 and Figure 8 illustrate the timing diagrams for serial data entry and extraction for the FIFO shown in Figure 6. Figure 9 illustrates the final The right-most (most significant) device is connected to the TTS inputs of all devices. Similarly, the ORE output of the most significant device is connected to the TOS inputs of all devices. As in the vertical expansion scheme, horizontal expansion does not sacrifice any of the 74F433 flexibility for serial/parallel input and output. www.fairchildsemi.com 6 Interlocking Circuitry—Most conventional FIFO designs provide status signal analogous to IRF and ORE. However, when these devices are operated in arrays, variations in unit-to-unit operating speed require external gating to ensure that all devices have completed an operation. The 74F433 incorporates simple but effective 'master/slave' interlocking circuitry to eliminate the need for external gating. Figure 10 is a conceptual logic diagram of the internal circuitry that determines master/slave operation. When MR and IES are LOW, the master latch is set. When TTS goes LOW, the initialization flip-flop is set. If the master latch is HIGH, the input register is immediately initialized and the initialization flip-flop reset. If the master latch is reset, the input register is not initialized until IES goes LOW. In array operation, activating TTS initiates a ripple input register initialization from the row master to the last slave. In the 74F433 array of Figure 6, devices 1 and 5 are the row masters; the other devices are slaves to the master in their rows. No slave in a given row initializes its input register until it has received a LOW on its IES input from a row master or a slave of higher priority. Similarly, the ORE outputs of slaves do not go HIGH until their inputs have gone HIGH. This interlocking scheme ensures that new input data may be accepted by the array when the IRF output of the final slave in that row goes HIGH and that output data for the array may be extracted when the ORE output of the final slave in the output row goes HIGH. A similar operation takes place for the output register. Either a TOS or TOP input initiates a load-from-stack operation and sets the ORE request flip-flop. If the master latch is set, the last output register flip-flop is set and the ORE line goes HIGH. If the master latch is reset, the ORE output is LOW until a Serial Output Enable (OES) input is received. FIGURE 5. A Horizontal Expansion Scheme 7 www.fairchildsemi.com 74F433 The row master is established by connecting its IES input to ground, while a slave receives its IES input from the IRF output of the next-higher priority device. When an array of 74F433 FIFOs is initialized with a HIGH on the MR inputs of all devices, the IRF outputs of all devices are HIGH. Thus, only the row master receives a LOW on the IES input during initialization. positions of bits in an expanded 74F433 FIFO resulting from a 2032-bit serial bit train. 74F433 FIGURE 6. A 127 x 16 FIFO Array FIGURE 7. Serial Data Entry for Array of Figure www.fairchildsemi.com 8 74F433 FIGURE 8. Serial Data Extraction for Array of Figure FIGURE 9. Final Position of a 2032-Bit Serial Input FIGURE 10. Conceptual Diagram, Interlocking Circuitry 9 www.fairchildsemi.com 74F433 Absolute Maximum Ratings(Note 1) Recommended Operating Conditions Storage Temperature −65°C to +150°C Ambient Temperature under Bias −55°C to +125°C Free Air Ambient Temperature Junction Temperature under Bias −55°C to +150°C Supply Voltage 0°C to +70°C +4.5V to +5.5V VCC Pin Potential to −0.5V to +7.0V Ground Pin Input Voltage (Note 2) −0.5V to +7.0V Input Current (Note 2) −30 mA to +5.0 mA Voltage Applied to Output in HIGH State (with VCC = 0V) Standard Output −0.5V to VCC 3-STATE Output −0.5V to +5.5V Note 1: Absolute maximum ratings are values beyond which the device may be damaged or have its useful life impaired. Functional operation under these conditions is not implied. Note 2: Either voltage limit or current limit is sufficient to protect inputs. Current Applied to Output in LOW State (Max) twice the rated IOL (mA) DC Electrical Characteristics Symbol Parameter Min Typ Max VCC VIL Input LOW Voltage 0.8 V VCD Input Clamp Diode Voltage −1.5 V VOH Output HIGH 10% VCC 2.4 IOH = 400 µA (ORE, IRF) Voltage 10% VCC 2.4 IOH = 5.7 mA (Qn, Qs) 5% VCC 2.7 5% VCC 2.7 Output LOW Voltage IIH Input HIGH Current IBVI Input HIGH Current V Conditions Input HIGH Voltage VOL 2.0 Units VIH Output HIGH Leakage Current VID Input Leakage Test IOD Circuit Current Input LOW Current IOZH Output Leakage Current IOZL Output Leakage Current IOS Output Short-Circuit Current ICC Power Supply Current www.fairchildsemi.com IIN = −18 mA V Min 0.50 V Min IOL = 16 mA (Qn, Qs) 5.0 µA Max VIN = 2.7V 7.0 µA Max 50 µA Max V 0.0 3.75 µA 0.0 −0.4 mA Max VIN = 0.5V 50 µA Max VOUT = 2.7V (Qn, Qs) 4.75 Output Leakage IIL Recognized as a LOW Signal Min IOH = 400 µA (ORE, IRF) IOH = 5.7 mA (Qn, Qs) 10% VCC Breakdown Test ICEX Recognized as a HIGH Signal −20 150 10 VIN = 7.0V VOUT = VCC IID = 1.9 µA All Other Pins Grounded VIOD = 150 mV All Other Pins Grounded −50 µA Max VOUT = 0.5V (Qn, Qs) −130 mA Max VOUT = 0V 215 mA Max 74F433 AC Electrical Characteristics Symbol tPHL Parameter Propagation Delay, Negative-Going CPSI to IRF Output tPLH Propagation Delay, TA = +25°C TA = 0°C to +70°C VCC = +5.0V VCC = +5.0V CL = 50 pF CL = 50 pF Min Max Min Max 2.0 17.0 2.0 18.0 Units Figure Number ns Figure 11 Figure 12 ns Figure 13 Figure 14 ns Figure 15 ns Figure 13 Figure 14 ns Figure 15 ns Figure 13 Figure 14 ns Figure 17 Figure 18 9.0 34.0 8.0 38.0 tPLH Propagation Delay, Negative-Going 4.0 25.0 3.0 27.0 tPHL CPSO to QS Output 5.0 20.0 5.0 21.0 tPLH Propagation Delay, Positive-Going 8.0 35.0 7.0 38.0 tPHL TOP to Q0–Q3 Outputs 7.0 30.0 7.0 32.0 7.0 25.0 6.0 28.0 6.0 26.0 6.0 28.0 13.0 48.0 12.0 51.0 13.0 45.0 12.0 50.0 4.0 22.0 4.0 23.0 7.0 31.0 6.0 35.0 9.0 38.0 8.0 44.0 ns 5.0 25.0 5.0 27.0 ns 7.0 28.0 7.0 31.0 ns 5.0 27.0 5.0 30.0 ns Negative-Going TTS to IRF tPHL Propagation Delay, Negative-Going CPSO to ORE tPHL Propagation Delay, Negative-Going TOP to ORE tPLH Propagation Delay, Positive-Going TOP to ORE tPLH Propagation Delay, Negative-Going TOS to Positive-Going ORE tPHL Propagation Delay, PositiveGoing PL to Negative-Going IRF tPLH Propagation Delay, NegativeGoing PL to Positive-Going IRF tPLH Propagation Delay, Positive-Going OES to ORE tPLH Propagation Delay Positive-IRF tPHL Propagation Delay Going IES to Positive-Going MR to ORE tPLH Propagation Delay MR to IRF tPZH Enable Time 1.0 16.0 1.0 18.0 tPZL OE to Q0–Q3 1.0 14.0 1.0 16.0 tPHZ Disable Time 1.0 10.0 1.0 12.0 tPLZ OE to Q0–Q3 1.0 23.0 1.0 30.0 tPZH Enable Time 1.0 10.0 1.0 12.0 tPZL Negative-Going OES to QS 1.0 14.0 1.0 15.0 tPHZ Disable Time 1.0 10.0 1.0 12.0 tPLZ Negative-Going OES to QS 1.0 14.0 1.0 16.0 tPZH Enable Time 1.0 35.0 1.0 42.0 tPZL TOS to QS 1.0 35.0 1.0 39.0 tDFT Fall-Through Time 0.2 0.9 0.2 1.0 tAP Parallel Appearance Time −20.0 −2.0 −20.0 −2.0 −20.0 5.0 −20.0 5.0 ORE to Q0–Q3 tAS Serial Appearance Time ORE to QS Figure 18 ns ns ns ns Figure 16 ns 11 www.fairchildsemi.com 74F433 AC Operating Requirements Symbol Parameter TA = +25°C TA = 0°C to +70°C VCC = +5.0V VCC = +5.0V Min tS(H) Setup Time, HIGH or LOW 7.0 Max Min Units Figure Number ns Figure 11 Figure 12 Max 7.0 tS(L) DS to Negative CPSI 7.0 7.0 tH(H) Hold Time, HIGH or LOW 2.0 2.0 tH(L) DS to CPSI 2.0 2.0 tS(L) Setup Time, LOW TTS to IRF, 0.0 0.0 ns Figure 11 Figure 12 Figure 17 Figure 18 0.0 0.0 ns Figure 13 Figure 14 8.0 9.0 ns Figure 12 30.0 33.0 Serial or Parallel Mode tS(L) Setup Time, LOW Negative-Going ORE to Negative-Going TOS tS(L) Setup Time, LOW Negative-Going IES to CPSI tS(L) Setup Time, LOW Negative-Going tS(H) Setup Time, HIGH or LOW 0.0 0.0 tS(L) Parallel Inputs to PL 0.0 0.0 tH(H) Hold Time, HIGH or LOW 4.0 4.0 tH(L) Parallel Inputs to PL 4.0 4.0 tW(H) CPSI Pulse Width 10.0 11.0 tW(L) HIGH or LOW 5.0 6.0 tW(H) PL Pulse Width, HIGH 7.0 9.0 ns 7.0 9.0 ns Figure 11 Figure 12 Figure 13 Figure 14 ns Figure 16 ns Figure 15 ns Figure 13 Figure 14 ns Figure 16 TTS to CPSI tW(L) ns ns TTS Pulse Width, LOW Serial or Parallel Mode tW(L) MR Pulse Width, LOW 7.0 9.0 tW(H) TOP Pulse Width 14.0 16.0 tW(L) HIGH or LOW 7.0 7.0 tW(H) CPSO Pulse Width 14.0 16.0 tW(L) HIGH or LOW 7.0 7.0 tREC Recovery Time 8.0 15.0 MR to Any Input www.fairchildsemi.com 12 Figure 11 Figure 12 Figure 17 Figure 18 74F433 Timing Waveforms Conditions: Stack not full, IES, PL LOW FIGURE 11. Serial Input, Unexpanded or Master Operation Conditions: Stack not full, IES HIGH when initiated, PL LOW FIGURE 12. Serial Input, Expanded Slave Operation Conditions: Data in stack, TOP HIGH, IES LOW when initiated, OES LOW FIGURE 13. Serial Output, Unexpanded or Master Operation 13 www.fairchildsemi.com 74F433 Timing Waveforms (Continued) Conditions: Data in stack, TOP HIGH, IES HIGH when initiated FIGURE 14. Serial Output, Slave Operation Conditions: IES LOW when initiated, OE, CPSO LOW; data available in stack FIGURE 15. Parallel Output, 4-Bit Word or Master in Parallel Expansion Conditions: TTS connected to IRF, TOS connected to ORE, IES, OES, OE, CPSO LOW, TOP HIGH FIGURE 16. Fall Through Time www.fairchildsemi.com 14 74F433 Timing Waveforms (Continued) Conditions: Stack not full, IES LOW when initialized NOTE A: TTS normally connected to IRF. NOTE B: If stack is full, IRF will stay LOW. FIGURE 17. Parallel Load Mode, 4-Bit Word (Unexpanded) or Master in Parallel Expansion Conditions: Stack not full, device initialized (Note 3) with IES HIGH Note 3: Initialization requires a master reset to occur after power has been applied. FIGURE 18. Parallel Load, Slave Mode 15 www.fairchildsemi.com 74F433 First-In First-Out (FIFO) Buffer Memory Physical Dimensions inches (millimeters) unless otherwise noted 24-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-100, 0.300 Wide Package Number N24C Fairchild does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and Fairchild reserves the right at any time without notice to change said circuitry and specifications. LIFE SUPPORT POLICY FAIRCHILD’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILD SEMICONDUCTOR CORPORATION. As used herein: 2. A critical component in any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and (c) whose failure to perform when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the user. www.fairchildsemi.com www.fairchildsemi.com 16