CY7C027V/027VN/027AV/028V CY7C037V/037AV/038V 3.3V 32K/64K x 16/18 Dual-Port Static RAM Features ■ ■ ■ True Dual-Ported memory cells which allow simultaneous access of the same memory location [1] ■ 32K x 16 organization (CY7C027V/027VN/027AV ) ■ 64K x 16 organization (CY7C028V) [2] ■ 32K x 18 organization (CY7C037V/037AV ) ■ 64K x 18 organization (CY7C038V) ■ 0.35 micron CMOS for optimum speed and power ■ High speed access: 15, 20, and 25 ns ■ Low operating power ■ Active: ICC = 115 mA (typical) ■ Standby: ISB3 = 10 μA (typical) ■ ■ ■ ■ ■ ■ ■ ■ ■ Fully asynchronous operation Automatic power down Expandable data bus to 32/36 bits or more using Master/Slave chip select when using more than one device On-chip arbitration logic Semaphores included to permit software handshaking between ports INT flag for port-to-port communication Separate upper-byte and lower-byte control Dual chip enables Pin select for Master or Slave Commercial and Industrial temperature ranges 100-pin Pb-free TQFP and 100-pin TQFP Logic Block Diagram R/WL UBL R/WR UBR CE0L CE1L CEL CE0R CE1R CER LBL LBR OEL OER [3] I/O8/9L–I/O15/17L [4] 8/9 8/9 8/9 8/9 I/O Control I/O0L–I/O7/8L [5] A0L–A14/15L [5] 15/16 Address Decode 15/16 [4] I/O0L–I/O7/8R Address Decode True Dual-Ported RAM Array 15/16 [5] A0R–A14/15R 15/16 A0L–A14/15L CEL OEL R/WL SEML BUSYL INTL UBL LBL I/O Control [3] I/O8/9L–I/O15/17R [5] A0R–A14/15R CER OER R/WR SEMR Interrupt Semaphore Arbitration [6] [6] M/S BUSYR INTR UBR LBR Notes 1. CY7C027V, CY7C027VN and CY7C027AV are functionally identical. 2. CY7C037V and CY7C037AV are functionally identical. 3. I/O8–I/O15 for x16 devices; I/O9–I/O17 for x18 devices. 4. I/O0–I/O7 for x16 devices; I/O0–I/O8 for x18 devices. 5. A0–A14 for 32K; A0–A15 for 64K devices. 6. BUSY is an output in master mode and an input in slave mode. Cypress Semiconductor Corporation Document #: 38-06078 Rev. *B • 198 Champion Court • San Jose, CA 95134-1709 • 408-943-2600 Revised December 09, 2008 [+] Feedback CY7C027V/027VN/027AV/028V CY7C037V/037AV/038V Pin Configurations A8R A7R A6R A5R A4R A3R A2R A1R A0R INTR BUSYR M/S GND BUSYL INTL NC A0L A1L A2L A3L A4L A5L A6L A7L A8L Figure 1. 100-Pin TQFP (Top View) 100 99 98 97 96 95 94 93 92 91 90 89 88 87 86 85 84 83 82 81 80 79 78 77 76 A9L 1 75 A9R A10L 2 74 A10R A11L 3 73 A11R A12L 4 72 A12R A13L 5 71 A13R A14L 6 70 A14R [1] A15L 7 69 A15R [1] NC 8 68 NC NC 9 67 NC LBL 10 66 LBR UBL 11 65 UBR 64 CE0R 63 CE1R 62 SEMR CY7C028V (64K x 16) CY7C027V/027VN/027AV (32K x 16) CE0L 12 CE1L 13 SEML 14 VCC 15 61 GND R/WL 16 60 R/WR OEL 17 59 OER GND 18 58 GND GND 19 57 GND I/O15L 20 56 I/O15R I/O14L 21 55 I/O14R I/O13L 22 54 I/O13R I/O12L 23 53 I/O12R I/O11L 24 52 I/O11R I/O10L 25 51 I/O10R NC I/O9R I/O8R I/O7R VCC I/O6R I/O5R I/O4R I/O3R I/O2R I/01R I/O0R GND I/O0L I/O1L GND I/O2L I/O3L I/O4L I/O5L I/O6L I/O7L VCC I/O8L I/O9L 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 Note 1. This pin is NC for CY7C027V/027VN/027AV. Document #: 38-06078 Rev. *B Page 2 of 18 [+] Feedback CY7C027V/027VN/027AV/028V CY7C037V/037AV/038V Pin Configurations (continued) A7R A6R A5R A4R A3R A2R A1R A0R INTR BUSYR M/S VCC GND GND BUSYL INTL A0L A1L A2L A3L A4L A5L A6L A7L A8L Figure 2. 100-Pin TQFP (Top View) 100 99 98 97 96 95 94 93 92 91 90 89 88 87 86 85 84 83 82 81 80 79 78 77 76 [2] A9L 1 75 A8R A10L 2 74 A9R A11L 3 73 A10R A12L 4 72 A11R A13L 5 71 A12R A14L 6 70 A13R A15L 7 69 A14R LBL 8 68 A15R [2] UBL 9 67 LBR CE0L 10 66 UBR CE1L 11 65 CE0R SEML 12 64 CE1R R/WL 13 63 SEMR OEL 14 62 R/WR VCC 15 61 GND GND 16 60 OER I/O17L 17 59 GND I/O16L 18 58 I/O17R GND 19 57 GND I/O15L 20 56 I/O16R I/O14L 21 55 I/O15R I/O13L 22 54 I/O14R I/O12L 23 53 I/O13R I/O11L 24 52 I/O12R I/O10L 25 51 I/O11R CY7C038V (64K x 18) CY7C037V/037AV (32K x 18) I/O10R I/O9R I/O8R I/O7R VCC I/O6R I/O5R I/O4R I/O3R I/O2R I/01R I/O0R GND I/O0L I/O1L GND I/O2L I/O3L I/O4L I/O5L I/O6L I/O7L VCC I/O8L I/O9L 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 Selection Guide -15 -20 -25 Unit Maximum Access Time Parameter 15 20 25 ns Typical Operating Current 125 120 115 mA Typical Standby Current for ISB1 (Both ports TTL level) 35 35 30 mA 10 μA 10 μA 10 μA μA Typical Standby Current for ISB3 (Both ports CMOS level) Note 2. This pin is NC for CY7C037V/037AV. Document #: 38-06078 Rev. *B Page 3 of 18 [+] Feedback CY7C027V/027VN/027AV/028V CY7C037V/037AV/038V Pin Definitions Left Port Right Port Description CE0L, CE1L CE0R, CE1R Chip Enable (CE is LOW when CE0 ≤ VIL and CE1 ≥ VIH) R/WL R/WR Read/Write Enable OEL OER Output Enable A0L–A15L A0R–A15R Address (A0–A14 for 32K; A0–A15 for 64K devices) I/O0L–I/O17L I/O0R–I/O17R Data Bus Input/Output (I/O0–I/O15 for x16 devices; I/O0–I/O17 for x18) SEML SEMR Semaphore Enable UBL UBR Upper Byte Select (I/O8–I/O15 for x16 devices; I/O9–I/O17 for x18 devices) LBL LBR Lower Byte Select (I/O0–I/O7 for x16 devices; I/O0–I/O8 for x18 devices) INTL INTR Interrupt Flag BUSYL BUSYR Busy Flag M/S Master or Slave Select VCC Power GND Ground NC No Connect Architecture The CY7C027V/027VN/027AV/028V and CY7037V/037AV/038V consist of an array of 32K and 64K words of 16 and 18 bits each of dual-port RAM cells, I/O and address lines, and control signals (CE, OE, R/W). These control pins permit independent access for reads or writes to any location in memory. To handle simultaneous writes/reads to the same location, a BUSY pin is provided on each port. Two interrupt (INT) pins can be utilized for port-to-port communication. Two semaphore (SEM) control pins are used for allocating shared resources. With the M/S pin, the devices can function as a master (BUSY pins are outputs) or as a slave (BUSY pins are inputs). The devices also have an automatic power down feature controlled by CE. Each port is provided with its own output enable control (OE), which allows data to be read from the device. Functional Description The CY7C027V/027VN/027AV/028V and CY7037V/037AV/038V are low power CMOS 32K, 64K x 16/18 dual-port static RAMs. Various arbitration schemes are included on the devices to handle situations when multiple processors access the same piece of data. Two ports are provided, permitting independent, asynchronous access for reads and writes to any location in memory. The devices can be utilized as stand-alone 16/18-bit dual-port static RAMs or multiple devices can be combined to function as a 32/36-bit or wider master/slave dual-port static RAM. An M/S pin is provided for implementing 32/36-bit or wider memory applications without the need for separate master and slave devices or additional discrete logic. Application areas include interprocessor/multiprocessor designs, communications status buffering, and dual-port video/graphics memory. Each port has independent control pins: chip enable (CE), read or write enable (R/W), and output enable (OE). Two flags are provided on each port (BUSY and INT). BUSY signals that the port is trying to access the same location currently being accessed by the other port. The interrupt flag (INT) permits communication between ports or Document #: 38-06078 Rev. *B systems by means of a mail box. The semaphores are used to pass a flag, or token, from one port to the other to indicate that a shared resource is in use. The semaphore logic is comprised of eight shared latches. Only one side can control the latch (semaphore) at any time. Control of a semaphore indicates that a shared resource is in use. An automatic power down feature is controlled independently on each port by a chip select (CE) pin. The CY7C027V/027VN/027AV/028V and CY7037V/037AV/038V are available in 100-pin Thin Quad Plastic Flatpacks (TQFP). Write Operation Data must be set up for a duration of tSD before the rising edge of R/W to guarantee a valid write. A write operation is controlled by either the R/W pin (see Figure 7) or the CE pin (see Figure 8). Required inputs for non-contention operations are summarized in Table 1. If a location is being written to by one port and the opposite port attempts to read that location, a port-to-port flowthrough delay must occur before the data is read on the output; otherwise the data read is not deterministic. Data is valid on the port tDDD after the data is presented on the other port. Read Operation When reading the device, the user must assert both the OE and CE pins. Data is available tACE after CE or tDOE after OE is asserted. If the user wishes to access a semaphore flag, then the SEM pin must be asserted instead of the CE pin, and OE must also be asserted. Interrupts The upper two memory locations may be used for message passing. The highest memory location (7FFF for the CY7C027V/027VN/027AV/37V, FFFF for the CY7C028V/38V) is the mailbox for the right port and the second-highest memory location (7FFE for the CY7C027V/027VN/027AV/037V/037AV, FFFE for the CY7C028V/38V) is the mailbox for the left port. When one port writes to the other port’s mailbox, an interrupt is Page 4 of 18 [+] Feedback CY7C027V/027VN/027AV/028V CY7C037V/037AV/038V generated to the owner. The interrupt is reset when the owner reads the contents of the mailbox. The message is user defined. Each port can read the other port’s mailbox without resetting the interrupt. The active state of the busy signal (to a port) prevents the port from setting the interrupt to the winning port. Also, an active busy to a port prevents that port from reading its own mailbox and, thus, resetting the interrupt to it. If an application does not require message passing, do not connect the interrupt pin to the processor’s interrupt request input pin. The operation of the interrupts and their interaction with Busy are summarized in Table 2. Busy The CY7C027V/027VN/027AV/028V and CY7037V/037AV/038V provide on-chip arbitration to resolve simultaneous memory location access (contention). If both ports’ CEs are asserted and an address match occurs within tPS of each other, the busy logic determines which port has access. If tPS is violated, one port definitely gains permission to the location, but it is not predictable which port gets that permission. BUSY is asserted tBLA after an address match or tBLC after CE is taken LOW. Master/Slave A M/S pin is provided to expand the word width by configuring the device as either a master or a slave. The BUSY output of the master is connected to the BUSY input of the slave. This allows the device to interface to a master device with no external components. Writing to slave devices must be delayed until after the BUSY input has settled (tBLC or tBLA), otherwise, the slave chip may begin a write cycle during a contention situation. When tied HIGH, the M/S pin allows the device to be used as a master and, therefore, the BUSY line is an output. BUSY can then be used to send the arbitration outcome to a slave. Semaphore Operation The CY7C027V/027VN/027AV/028V and CY7037V/037AV/038V provide eight semaphore latches, which are separate from the dual-port memory locations. Semaphores Document #: 38-06078 Rev. *B are used to reserve resources that are shared between the two ports.The state of the semaphore indicates that a resource is in use. For example, if the left port wants to request a given resource, it sets a latch by writing a zero to a semaphore location. The left port then verifies its success in setting the latch by reading it. After writing to the semaphore, SEM or OE must be deasserted for tSOP before attempting to read the semaphore. The semaphore value is available tSWRD + tDOE after the rising edge of the semaphore write. If the left port was successful (reads a zero), it assumes control of the shared resource, otherwise (reads a one) it assumes the right port has control and continues to poll the semaphore. When the right side has relinquished control of the semaphore (by writing a one), the left side succeeds in gaining control of the semaphore. If the left side no longer requires the semaphore, a one is written to cancel its request. Semaphores are accessed by asserting SEM LOW. The SEM pin functions as a chip select for the semaphore latches (CE must remain HIGH during SEM LOW). A0–2 represents the semaphore address. OE and R/W are used in the same manner as a normal memory access. When writing or reading a semaphore, the other address pins have no effect. When writing to the semaphore, only I/O0 is used. If a zero is written to the left port of an available semaphore, a one appears at the same semaphore address on the right port. That semaphore can now only be modified by the side showing zero (the left port in this case). If the left port now relinquishes control by writing a one to the semaphore, the semaphore is set to one for both sides. However, if the right port had requested the semaphore (written a zero) while the left port had control, the right port would immediately own the semaphore as soon as the left port released it. Table 3 shows sample semaphore operations. When reading a semaphore, all sixteen/eighteen data lines output the semaphore value. The read value is latched in an output register to prevent the semaphore from changing state during a write from the other port. If both ports attempt to access the semaphore within tSPS of each other, the semaphore is definitely obtained by one side or the other, but there is no guarantee which side controls the semaphore. Page 5 of 18 [+] Feedback CY7C027V/027VN/027AV/028V CY7C037V/037AV/038V DC Input Voltage[2] .................................. –0.5V to VCC+0.5V Maximum Ratings Exceeding maximum ratings may shorten the useful life of the device. User guidelines are not tested. Output Current into Outputs (LOW)............................. 20 mA Static Discharge Voltage.......................................... > 1100V Storage Temperature ................................. –65°C to +150°C Latch-up Current.................................................... > 200 mA Ambient Temperature with Power Applied ............................................ –55°C to +125°C Operating Range Supply Voltage to Ground Potential................–0.5V to +4.6V Range Ambient Temperature VCC DC Voltage Applied to Outputs in High-Z State ........................... –0.5V to VCC+0.5V Commercial 0°C to +70°C 3.3V ± 300 mV Industrial[3] –40°C to +85°C 3.3V ± 300 mV Electrical Characteristics Over the Operating Range CY7C027V/027VN/027AV/028V/CY7C037V/037AV/038V Parameter Description VOH Output HIGH Voltage (VCC=Min., IOH= –4.0 mA) VOL Output LOW Voltage (VCC=Min., IOH= +4.0 mA) VIH Input HIGH Voltage VIL Input LOW Voltage IIX Input Leakage Current IOZ Output Leakage Current ICC Operating Current (VCC=Max. IOUT=0 mA) Outputs Disabled Com’l. Standby Current (Both Ports TTL Level) CEL & CER ≥ VIH, f=fMAX Com’l. ISB1 -15 -20 Min Typ Max Min Typ 2.4 2.4 −5 10 –10 125 185 35 50 Ind.[3] Ind.[3] −5 10 –10 120 175 140 195 35 45 45 55 Standby Current (One Port TTL Level) Com’l. CEL | CER ≥ VIH, f=fMAX Ind.[3] 80 120 75 110 85 120 ISB3 Standby Current (Both Ports CMOS Level) CEL & CER ≥ VCC−0.2V, f=0 10 250 10 250 10 250 75 105 70 95 80 105 ISB4 Ind. [3] Standby Current (One Port CMOS Lev- Com’l. el) CEL | CER ≥ VIH, f=fMAX[4] Ind.[3] 0.4 5 ISB2 Com’l. V V V 0.8 5 Unit Max 2.2 0.8 –10 Typ 0.4 2.2 −5 Min 2.4 0.4 2.2 -25 Max 0.8 V 5 μA 10 μA 115 165 mA 30 40 mA 65 95 mA 10 250 μA 60 80 mA mA mA mA μA mA Capacitance[5] Parameter Description CIN Input Capacitance COUT Output Capacitance Test Conditions TA = 25°C, f = 1 MHz, VCC = 3.3V Max Unit 10 pF 10 pF Notes 2. Pulse width < 20 ns. 3. Industrial parts are available in CY7C028V and CY7C038V only. 4. fMAX = 1/tRC = All inputs cycling at f = 1/tRC (except output enable). f = 0 means no address or control lines change. This applies only to inputs at CMOS level standby ISB3. 5. Tested initially and after any design or process changes that may affect these parameters. Document #: 38-06078 Rev. *B Page 6 of 18 [+] Feedback CY7C027V/027VN/027AV/028V CY7C037V/037AV/038V Figure 3. AC Test Loads and Waveforms 3.3V 3.3V R1 = 590Ω C = 30 pF RTH = 250Ω OUTPUT OUTPUT R1 = 590Ω OUTPUT C = 30 pF R2 = 435Ω C = 5 pF R2 = 435Ω VTH = 1.4V (a) Normal Load (Load 1) (c) Three-State Delay (Load 2) (Used for tLZ, tHZ, tHZWE, & tLZWE including scope and jig) (b) Thévenin Equivalent (Load 1) ALL INPUT PULSES 3.0V 10% GND 90% 10% 90% ≤ 3 ns ≤ 3 ns Switching Characteristics Over the Operating Range[6] CY7C027V/027VN/027AV/028V/ CY7C037V/037AV/038V Parameter Description -15 Min -20 Max Min Unit -25 Max Min Max Read Cycle tRC Read Cycle Time tAA Address to Data Valid tOHA Output Hold From Address Change tACE[7] CE LOW to Data Valid tDOE OE LOW to Data Valid tLZOE[8, 9, 10] OE LOW to Low Z tHZOE[8, 9, 10] OE HIGH to High Z tLZCE[8, 9, 10] tHZCE[8, 9, 10] tPU[10] tPD[10] tABE[7] CE LOW to Low Z 15 3 25 20 3 15 3 12 3 10 3 3 0 ns ns 13 ns ns 15 ns 15 ns 3 12 0 ns 25 3 12 10 ns 25 20 10 3 CE HIGH to High Z CE LOW to Power Up 20 15 ns 0 ns CE HIGH to Power Down 15 20 25 ns Byte Enable Access Time 15 20 25 ns Write Cycle tWC Write Cycle Time 15 20 25 tSCE[7] CE LOW to Write End 12 16 20 ns ns tAW Address Valid to Write End 12 16 20 ns tHA Address Hold From Write End 0 0 0 ns tSA[7] Address Setup to Write Start 0 0 0 ns tPWE Write Pulse Width 12 17 22 ns tSD Data Setup to Write End 10 12 15 ns Notes 6. Test conditions assume signal transition time of 3 ns or less, timing reference levels of 1.5V, input pulse levels of 0 to 3.0V, and output loading of the specified IOI/IOH and 30 pF load capacitance. 7. To access RAM, CE=L, UB=L, SEM=H. To access semaphore, CE=H and SEM=L. Either condition must be valid for the entire tSCE time. 8. At any given temperature and voltage condition for any given device, tHZCE is less than tLZCE and tHZOE is less than tLZOE. 9. Test conditions used are Load 2. 10. This parameter is guaranteed by design, but it is not production tested. For information on port-to-port delay through RAM cells from writing port to reading port, refer to Figure 11. Document #: 38-06078 Rev. *B Page 7 of 18 [+] Feedback CY7C027V/027VN/027AV/028V CY7C037V/037AV/038V Switching Characteristics Over the Operating Range[6](continued) CY7C027V/027VN/027AV/028V/ CY7C037V/037AV/038V Parameter Description -15 Min -20 Max 0 Min Unit -25 Max Min 0 Max tHD Data Hold From Write End tHZWE[9, 10] R/W LOW to High Z 0 tLZWE[9 ,10] R/W HIGH to Low Z tWDD[36] tDDD[36] Write Pulse to Data Delay 30 40 50 ns Write Data Valid to Read Data Valid 25 30 35 ns tBLA BUSY LOW from Address Match 15 20 20 ns tBHA BUSY HIGH from Address Mismatch 15 20 20 ns tBLC BUSY LOW from CE LOW 15 20 20 ns tBHC BUSY HIGH from CE HIGH tPS Port Setup for Priority 5 5 5 ns tWB R/W HIGH after BUSY (Slave) 0 0 0 ns tWH R/W HIGH after BUSY HIGH (Slave) 13 tBDD[13] BUSY HIGH to Data Valid 10 3 12 ns 15 3 ns 3 ns Busy Timing[11] 15 16 15 17 ns 17 ns 15 20 25 ns [11] Interrupt Timing tINS INT Set Time 15 20 20 ns tINR INT Reset Time 15 20 20 ns Semaphore Timing tSOP SEM Flag Update Pulse (OE or SEM) 10 10 12 ns tSWRD SEM Flag Write to Read Time 5 5 5 ns tSPS SEM Flag Contention Window 5 5 5 ns tSAA SEM Address Access Time Data Retention Mode The CY7C027V/027VN/027AV/028V and CY7037V/037AV/038V are designed with battery backup in mind. Data retention voltage and supply current are guaranteed over temperature. The following rules ensure data retention: 1. Chip enable (CE) must be held HIGH during data retention, within VCC to VCC – 0.2V. 2. CE must be kept between VCC – 0.2V and 70% of VCC during the power up and power down transitions. 3. The RAM can begin operation >tRC after VCC reaches the minimum operating voltage (3.0 volts). 15 20 25 ns Timing Data Retention Mode VCC 3.0V VCC > 2.0V 3.0V VCC to VCC – 0.2V CE Parameter ICCDR1 Test Conditions[14] At VCCDR = 2V tRC V IH Max Unit 50 μA Notes 11. For information on port-to-port delay through RAM cells from writing port to reading port, refer to Figure 11 waveform. 12. Test conditions used are Load 1. 13. tBDD is a calculated parameter and is the greater of tWDD–tPWE (actual) or tDDD–tSD (actual). 14. CE = VCC, Vin = GND to VCC, TA = 25° C. This parameter is guaranteed but not tested. Document #: 38-06078 Rev. *B Page 8 of 18 [+] Feedback CY7C027V/027VN/027AV/028V CY7C037V/037AV/038V Switching Waveforms Figure 4. Read Cycle No. 1 (Either Port Address Access)[15, 16, 17] tRC ADDRESS tOHA DATA OUT tAA tOHA PREVIOUS DATA VALID DATA VALID Figure 5. Read Cycle No. 2 (Either Port CE/OE Access)[15, 18, 19] tACE CE and LB or UB tHZCE tDOE OE tHZOE tLZOE DATA VALID DATA OUT tLZCE tPU tPD ICC CURRENT ISB Figure 6. Read Cycle No. 3 (Either Port)[15, 17, 18, 19] tRC ADDRESS tAA tOHA UB or LB tHZCE tLZCE tABE CE tHZCE tACE tLZCE DATA OUT Notes 15. R/W is HIGH for read cycles. 16. Device is continuously selected CE = VIL and UB or LB = VIL. This waveform cannot be used for semaphore reads. 17. OE = VIL. 18. Address valid prior to or coincident with CE transition LOW. 19. To access RAM, CE = VIL, UB or LB = VIL, SEM = VIH. To access semaphore, CE = VIH, SEM = VIL. Document #: 38-06078 Rev. *B Page 9 of 18 [+] Feedback CY7C027V/027VN/027AV/028V CY7C037V/037AV/038V Switching Waveforms(continued) Figure 7. Write Cycle No. 1: R/W Controlled Timing[20, 21, 22, 23] tWC ADDRESS tHZOE [26] OE tAW CE [24,25] tPWE[23] tSA tHA R/W tHZWE[26] DATA OUT tLZWE NOTE 27 NOTE 27 tSD tHD DATA IN Figure 8. Write Cycle No. 2: CE Controlled Timing[20, 21, 22, 28] tWC ADDRESS tAW CE [24,25] tSA tSCE tHA R/W tSD tHD DATA IN Notes 20. R/W must be HIGH during all address transitions. 21. A write occurs during the overlap (tSCE or tPWE) of a LOW CE or SEM and a LOW UB or LB. 22. tHA is measured from the earlier of CE or R/W or (SEM or R/W) going HIGH at the end of write cycle. 23. If OE is LOW during a R/W controlled write cycle, the write pulse width must be the larger of tPWE or (tHZWE + tSD) to allow the I/O drivers to turn off and data to be placed on the bus for the required tSD. If OE is HIGH during an R/W controlled write cycle, this requirement does not apply and the write pulse can be as short as the specified tPWE. 24. To access RAM, CE = VIL, SEM = VIH. 25. To access upper byte, CE = VIL, UB = VIL, SEM = VIH. To access lower byte, CE = VIL, LB = VIL, SEM = VIH. 26. Transition is measured ±500 mV from steady state with a 5 pF load (including scope and jig). This parameter is sampled and not 100% tested. 27. During this period, the I/O pins are in the output state, and input signals must not be applied. 28. If the CE or SEM LOW transition occurs simultaneously with or after the R/W LOW transition, the outputs remain in the high impedance state. Document #: 38-06078 Rev. *B Page 10 of 18 [+] Feedback CY7C027V/027VN/027AV/028V CY7C037V/037AV/038V Switching Waveforms(continued) Figure 9. Semaphore Read After Write Timing, Either Side[29] tSAA A0–A 2 VALID ADRESS VALID ADRESS tAW tACE tHA SEM tOHA tSCE tSOP tSD I/O 0 DATAIN VALID tSA tPWE DATAOUT VALID tHD R/W tSWRD tDOE tSOP OE WRITE CYCLE READ CYCLE Figure 10. Timing Diagram of Semaphore Contention[30, 31, 32] A0L –A2L MATCH R/WL SEM L tSPS A 0R –A 2R MATCH R/WR SEM R Notes 29. CE = HIGH for the duration of the above timing (both write and read cycle). 30. I/O0R = I/O0L = LOW (request semaphore); CER = CEL = HIGH. 31. Semaphores are reset (available to both ports) at cycle start. 32. If tSPS is violated, the semaphore is definitely obtained by one side or the other, but which side gets the semaphore is unpredictable. Document #: 38-06078 Rev. *B Page 11 of 18 [+] Feedback CY7C027V/027VN/027AV/028V CY7C037V/037AV/038V Switching Waveforms(continued) Figure 11. Timing Diagram of Read with BUSY (M/S=HIGH)[33] tWC ADDRESSR MATCH tPWE R/WR tSD DATA INR tHD VALID tPS ADDRESSL MATCH tBLA tBHA BUSYL tBDD tDDD DATA OUTL VALID tWDD Figure 12. Write Timing with Busy Input (M/S=LOW) tPWE R/W BUSY tWB tWH Note 33. CEL = CER = LOW. Document #: 38-06078 Rev. *B Page 12 of 18 [+] Feedback CY7C027V/027VN/027AV/028V CY7C037V/037AV/038V Switching Waveforms(continued) Figure 13. Busy Timing Diagram No. 1 (CE Arbitration)[34] CELValid First: ADDRESS L,R ADDRESS MATCH CEL tPS CER tBLC tBHC BUSYR CER Valid First: ADDRESS L,R ADDRESS MATCH CER tPS CE L tBLC tBHC BUSY L Figure 14. Busy Timing Diagram No. 2 (Address Arbitration)[34] Left Address Valid First: tRC or tWC ADDRESS L ADDRESS MATCH ADDRESS MISMATCH tPS ADDRESSR tBLA tBHA BUSY R Right Address Valid First: tRC or tWC ADDRESSR ADDRESS MATCH ADDRESS MISMATCH tPS ADDRESSL tBLA tBHA BUSY L Note 34. If tPS is violated, the busy signal is asserted on one side or the other, but there is no guarantee to which side BUSY is asserted. Document #: 38-06078 Rev. *B Page 13 of 18 [+] Feedback CY7C027V/027VN/027AV/028V CY7C037V/037AV/038V Switching Waveforms(continued) Figure 15. Interrupt Timing Diagrams Left Side Sets INTR : ADDRESSL tWC WRITE 7FFF (FFFF for CY7C028V/38V) tHA[35] CE L R/W L INT R tINS [36] Right Side Clears INT R : tRC READ 7FFF (FFFF for CY7C028V/38V) ADDRESSR CE R tINR [36] R/WR OE R INTR Right Side Sets INT L: tWC ADDRESSR WRITE 7FFE (FFFE for CY7C028V/38V) tHA[35] CE R R/W R INT L [36] tINS Left Side Clears INT L: tRC READ 7FFE (FFFF for CY7C028V/38V) ADDRESSR CE L tINR[36] R/W L OE L INT L Notes 35. tHA depends on which enable pin (CEL or R/WL) is deasserted first. 36. tINS or tINR depends on which enable pin (CEL or R/WL) is asserted last. Document #: 38-06078 Rev. *B Page 14 of 18 [+] Feedback CY7C027V/027VN/027AV/028V CY7C037V/037AV/038V Table 1. Non-Contending Read/Write Inputs Outputs CE R/W OE UB LB SEM I/O9–I/O17 I/O0–I/O8 H X X X X H X X X H H H High Z High Z Deselected: Power Down L L X L H H Data In High Z Write to Upper Byte Only L L X H L H High Z Data In Write to Lower Byte Only L L X L L H Data In Data In Write to Both Bytes L H L L H H Data Out High Z Read Upper Byte Only L H L H L H High Z Data Out Read Lower Byte Only L H L L L H Data Out Data Out Read Both Bytes X X H X X X High Z High Z Outputs Disabled H H L X X L Data Out Data Out Read Data in Semaphore Flag X H L H H L Data Out Data Out Read Data in Semaphore Flag H X X X L Data In Data In Write DIN0 into Semaphore Flag X X H H L Data In Data In Write DIN0 into Semaphore Flag High Z Operation High Z Deselected: Power Down L X X L X L Not Allowed L X X X L L Not Allowed Table 2. Interrupt Operation Example (assumes BUSYL=BUSYR=HIGH)[37] Left Port Function Right Port R/WL CEL OEL A0L–14L INTL R/WR CER OER A0R–14R INTR Set Right INTR Flag L L X 7FFF X X X X X L[39] Reset Right INTR Flag X X X X X X L L 7FFF H[38] X L[38] L L X 7FFE X 7FFE H[39] X X X X X Set Left INTL Flag Reset Left INTL Flag X X X X L L Table 3. Semaphore Operation Example Function No action I/O0–I/O17 Left I/O0–I/O17 Right 1 1 Status Semaphore free Left port writes 0 to semaphore 0 1 Left port has semaphore token Right port writes 0 to semaphore 0 1 No change. Right side has no write access to semaphore Left port writes 1 to semaphore 1 0 Right port obtains semaphore token Left port writes 0 to semaphore 1 0 No change. Left port has no write access to semaphore Right port writes 1 to semaphore 0 1 Left port obtains semaphore token Left port writes 1 to semaphore 1 1 Semaphore free Right port writes 0 to semaphore 1 0 Right port has semaphore token Right port writes 1 to semaphore 1 1 Semaphore free Left port writes 0 to semaphore 0 1 Left port has semaphore token Left port writes 1 to semaphore 1 1 Semaphore free Notes 37. A0L–15L and A0R–15R,FFFF/FFFE for the CY7C028V/038V. 38. If BUSYR=L, then no change. 39. If BUSYL=L, then no change. Document #: 38-06078 Rev. *B Page 15 of 18 [+] Feedback CY7C027V/027VN/027AV/028V CY7C037V/037AV/038V Ordering Information 32K x16 3.3V Asynchronous Dual-Port SRAM Speed (ns) 15 20 25 Ordering Code Package Name Package Type 100-Pin Thin Quad Flat Pack Operating Range CY7C027V-15AC A100 Commercial CY7C027V-15AXC A100 100-Pin Pb-Free Thin Quad Flat Pack Commercial CY7C027VN-15AXC A100 100-Pin Pb-Free Thin Quad Flat Pack Commercial CY7C027V-20AC A100 100-Pin Thin Quad Flat Pack Commercial CY7C027V-20AXC A100 100-Pin Pb-Free Thin Quad Flat Pack Commercial CY7C027V-25AC A100 100-Pin Thin Quad Flat Pack Commercial CY7C027V-25AXC A100 100-Pin Pb-Free Thin Quad Flat Pack Commercial CY7C027AV-25AXI A100 100-Pin Pb-Free Thin Quad Flat Pack Industrial 64K x16 3.3V Asynchronous Dual-Port SRAM Speed (ns) 15 20 25 Ordering Code Package Name CY7C028V-15AC A100 CY7C028V-15AXC CY7C028V-20AC Package Type Operating Range 100-Pin Thin Quad Flat Pack Commercial A100 100-Pin Pb-Free Thin Quad Flat Pack Commercial A100 100-Pin Thin Quad Flat Pack Commercial CY7C028V-20AXC A100 100-Pin Pb-Free Thin Quad Flat Pack Commercial CY7C028V-20AI A100 100-Pin Thin Quad Flat Pack Industrial CY7C028V-20AXI A100 100-Pin Pb-Free Thin Quad Flat Pack Industrial CY7C028V-25AC A100 100-Pin Thin Quad Flat Pack Commercial CY7C028V-25AXC A100 100-Pin Pb-Free Thin Quad Flat Pack Commercial 32K x18 3.3V Asynchronous Dual-Port SRAM Speed (ns) 15 20 25 Ordering Code Package Name Package Type Operating Range CY7C037V-15AC A100 100-Pin Thin Quad Flat Pack Commercial CY7C037V-15AXC A100 100-Pin Pb-Free Thin Quad Flat Pack Commercial CY7C037V-20AC A100 100-Pin Thin Quad Flat Pack Commercial CY7C037AV-20AXC A100 100-Pin Pb-Free Thin Quad Flat Pack Commercial CY7C037V-25AC A100 100-Pin Thin Quad Flat Pack Commercial CY7C037V-25AXC A100 100-Pin Pb-Free Thin Quad Flat Pack Commercial 64K x18 3.3V Asynchronous Dual-Port SRAM Speed (ns) 15 20 25 Ordering Code Package Name Package Type Operating Range CY7C038V-15AC A100 100-Pin Thin Quad Flat Pack Commercial CY7C038V-15AXC A100 100-Pin Pb-Free Thin Quad Flat Pack Commercial CY7C038V-20AC A100 100-Pin Thin Quad Flat Pack Commercial CY7C038V-20AXC A100 100-Pin Pb-Free Thin Quad Flat Pack Commercial CY7C038V-20AI A100 100-Pin Thin Quad Flat Pack Industrial CY7C038V-20AXI A100 100-Pin Pb-Free Thin Quad Flat Pack Industrial CY7C038V-25AC A100 100-Pin Thin Quad Flat Pack Commercial CY7C038V-25AXC A100 100-Pin Pb-Free Thin Quad Flat Pack Commercial Document #: 38-06078 Rev. *B Page 16 of 18 [+] Feedback CY7C027V/027VN/027AV/028V CY7C037V/037AV/038V Package Diagram Figure 16. 100-Pin Pb-Free Thin Plastic Quad Flat Pack (TQFP) A100 51-85048-*C Document #: 38-06078 Rev. *B Page 17 of 18 [+] Feedback CY7C027V/027VN/027AV/028V CY7C037V/037AV/038V Document History Page Document Title: CY7C027V/027VN/027AV/CY7C028V/037V/037AV/038V 3.3V 32K/64K x 16/18 Dual Port Static RAM Document Number: 38-06078 Rev. ECN No. Orig. of Change Submission Date ** 237626 YDT 6/30/04 *A 259110 JHX See ECN Added Pb-Free packaging information. *B 2623540 VKN/PYRS 12/17/08 Added CY7C027VN, CY7C027AV and CY7C037AV parts Updated Ordering information table Description of Change Converted data sheet from old spec 38-00670 to conform with new data sheet. Removed cross information from features section Sales, Solutions, and Legal Information Worldwide Sales and Design Support Cypress maintains a worldwide network of offices, solution centers, manufacturer’s representatives, and distributors. To find the office closest to you, visit us at cypress.com/sales. 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Furthermore, Cypress does not authorize its products for use as critical components in life-support systems where a malfunction or failure may reasonably be expected to result in significant injury to the user. The inclusion of Cypress products in life-support systems application implies that the manufacturer assumes all risk of such use and in doing so indemnifies Cypress against all charges. Any Source Code (software and/or firmware) is owned by Cypress Semiconductor Corporation (Cypress) and is protected by and subject to worldwide patent protection (United States and foreign), United States copyright laws and international treaty provisions. Cypress hereby grants to licensee a personal, non-exclusive, non-transferable license to copy, use, modify, create derivative works of, and compile the Cypress Source Code and derivative works for the sole purpose of creating custom software and or firmware in support of licensee product to be used only in conjunction with a Cypress integrated circuit as specified in the applicable agreement. Any reproduction, modification, translation, compilation, or representation of this Source Code except as specified above is prohibited without the express written permission of Cypress. Disclaimer: CYPRESS MAKES NO WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, WITH REGARD TO THIS MATERIAL, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. Cypress reserves the right to make changes without further notice to the materials described herein. Cypress does not assume any liability arising out of the application or use of any product or circuit described herein. Cypress does not authorize its products for use as critical components in life-support systems where a malfunction or failure may reasonably be expected to result in significant injury to the user. The inclusion of Cypress’ product in a life-support systems application implies that the manufacturer assumes all risk of such use and in doing so indemnifies Cypress against all charges. Use may be limited by and subject to the applicable Cypress software license agreement. Document #: 38-06078 Rev. *B Revised December 09, 2008 Page 18 of 18 All products and company names mentioned in this document may be the trademarks of their respective holders. [+] Feedback