HIGH-SPEED 3.3V 64K x 16 BANK-SWITCHABLE DUAL-PORTED SRAM WITH EXTERNAL BANK SELECTS
Features
◆
IDT70V7288S/L
◆ ◆ ◆
◆
64K x 16 Bank-Switchable Dual-Ported SRAM Architecture – Four independent 16K x 16 banks – 1 Megabit of memory on chip Fast asynchronous address-to-data access time: 15ns User-controlled input pins included for bank selects Independent port controls with asynchronous address & data busses Four 16-bit mailboxes available to each port for interprocessor communications; interrupt option
◆ ◆
◆ ◆ ◆ ◆
Functional Block Diagram
R/WL CE0L CE1L UBL LBL OEL
D E DS NN EG M SI ME OD C EW RE TN O N
MUX CONTROL LOGIC 16Kx16 MEMORY ARRAY (BANK 0) MUX MUX CONTROL LOGIC R/WR CE0R CE1R UBR LBR OER I/O8L-15L I/O0L-7L I/O CONTROL I/O CONTROL A13L A0L(1) ADDRESS DECODE 16Kx16 MEMORY ARRAY (BANK 1) MUX ADDRESS DECODE A13R A0R(1) BA1L BA0L BANK DECODE BANK DECODE BA1R BA0R MUX 16Kx16 MEMORY ARRAY (BANK 3) MUX BKSEL3(2) BKSEL0(2) BANK SELECT A5L (1) A0L (1) LBL/UBL OEL R/WL CEL MAILBOX INTERRUPT LOGIC A5R(1) A0R(1) LBR/UBR OER R/WR CER MBSELL INTL
Interrupt flags with programmable masking Dual Chip Enables allow for depth expansion without external logic UB and LB are available for x8 or x16 bus matching LVTTL-compatible, single 3.3V (±5%) power supply Available in a 100-pin Thin Quad Flatpack (14mm x 14mm) Industrial temperature range (-40°C to +85°C) is available for selected speeds
R O F
I/O8R-15R I/O0R-7R
MBSELR INTR
4077 drw 01
NOTES: 1. The first six address pins for each port serve dual functions. When MBSEL = VIH, the pins serve as memory address inputs. When MBSEL = VIL, the pins serve as mailbox address inputs. 2. Each bank has an input pin assigned that allows the user to toggle the assignment of that bank between the two ports. Refer to Truth Table I for more details.
JUNE 2000
1
©2000 Integrated Device Technology, Inc. D SC-4077/6
IDT70V7288S/L 64K x 16 3.3V Bank-Switchable Dual-Ported SRAM with External Bank Selects
Industrial and Commercial Temperature Ranges
Description
The IDT70V7288 is a high-speed 64K x 16 (1M bit) Bank-Switchable Dual-Ported SRAM organized into four independent 16K x 16 banks. The device has two independent ports with separate controls, addresses, and I/O pins for each port, allowing each port to asynchronously access any 16K x 16 memory block not already accessed by the other port. Accesses by the ports into specific banks are controlled via bank select pin inputs under the user's control. Mailboxes are provided to allow inter-processor communications. Interrupts are provided to indicate mailbox writes have occurred. An automatic power down feature controlled by the chip enables (CE0 and CE1) permits the onchip circuitry of each port to enter a very low standby power mode and allows fast depth expansion. The IDT70V7288 offers a maximum address-to-data access time as fast as 15ns, and is packaged in a 100-pin Thin Quad Flatpack (TQFP). the right port (See Truth Table IV). Once a bank is assigned to a particular port, the port has full access to read and write within that bank. Each port can be assigned as many banks within the array as needed, up to and including all four banks. The IDT70V7288 provides mailboxes to allow inter-processor communications. Each port has four 16-bit mailbox registers available to which it can write and read and which the opposite port can read only. These mailboxes are external to the common SRAM array, and are accessed by setting MBSEL = VIL while setting CE = VIH. Each mailbox has an associated interrupt: a port can generate an interrupt to the opposite port by writing to the upper byte of any one of its four 16-bit mailboxes. The interrupted port can clear the interrupt by reading the upper byte. This read will not alter the contents of the mailbox. If desired, any source of interrupt can be independently masked via software. Two registers are provided to permit interpretation of interrupts: the Interrupt Cause Register and the Interrupt Status Register. The Interrupt Cause Register gives the user a snapshot of what has caused the interrupt to be generated - the specific mailbox written to. The information in this register provides post-mask signals: Interrupt sources that have been masked will not be updated. The Interrupt Status Register gives the user the status of all bits that could potentially cause an interrupt regardless of whether they have been masked. Truth Table V gives a detailed explanation of the use of these registers.
Functionality
The IDT70V7288 is a high-speed asynchronous 64K x 16 BankSwitchable Dual-Ported SRAM, organized in four 16K x 16 banks. The two ports are permitted independent, simultaneous access into separate banks within the shared array. There are four user-controlled Bank Select input pins, and each of these pins is associated with a specific bank within the memory array. Access to a specific bank is gained by placing the associated Bank Select pin in the appropriate state: VIH assigns the bank to the left port, and VIL assigns the bank to
D E DS NN EG M SI ME OD C EW RE TN O N
R O F
6.42 2
IDT70V7288S/L 64K x 16 3.3V Bank-Switchable Dual-Ported SRAM with External Bank Selects
Industrial and Commercial Temperature Ranges
Pin
Configurations(1,2,3)
INDEX
A5L A4L A3L A2L A1L A0L BA1L BA0L A12L NC BKSEL1 INTL GND GND INTR BKSEL2 A12R BA0R BA1R A0R A1R A2R A3R A4R A5R
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 100 99 98 97 96 95 94 93 92 91 90 89 88 87 86 85 84 83 82 81 80 79 78 77 76 75 74 73 72 71 70 69 68 67 66 65 64 63 62 61 60 59 58 57 56 55 54 53 52
NOTES: 1. All VCC pins must be connected to power supply. 2. All GND pins must be connected to ground supply. 3. Package body is approximately 14mm x 14mm x 1.4mm. 4. This package code is used to reference the package diagram. 5. This text does not indicate orientation of the actual part-marking.
D E DS NN EG M SI ME OD C EW RE TN O N
51 25 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
A6L A7L A8L A9L A10L A11L A13L NC BKSEL0 LBL UBL CE0L CE1L MBSELL Vcc R/WL OEL GND GND I/O15L I/O14L I/O13L I/O12L I/O11L I/O10L
IDT70V7288PF PN100-1(4) 100-Pin TQFP Top View(5)
A6R A7R A8R A9R A10R A11R A13R NC BKSEL3 LBR UBR CE0R CE1R , MBSELR GND R/WR OER GND GND I/O15R I/O14R I/O13R I/O12R I/O11R I/O10R
R O F
I/O9L I/O8L Vcc I/O7L I/O6L I/O5L I/O4L I/O3L I/O2L GND I/O1L I/O0L GND I/O0R I/O1R I/O2R I/O3R I/O4R I/O5R I/O6R Vcc I/O7R I/O8R I/O9R NC
4077 drw 02
Pin Names
A0 - A13(1,6) BA0 - BA1(1) MBSEL(1)
Address Inputs
Bank Address Inputs Mailbox Access Control Gate Bank Select Inputs Read/Write Enable Output Enable Chip Enables
BKSEL0-3(2) R/W
(1)
OE(1)
CE0, CE1 UB, L B(1)
(1)
I/O Byte Enables Bidirectional Data Input/Output Interrupt Flag (Output)(3) 3.3VPower Ground
4077 tbl 01
I/O0 - I/O15(1) INT
(1)
VCC(4) GND
(5)
NOTES: 1. Duplicated per port. 2. Each bank has an input pin assigned that allows the user to toggle the assignment of that bank between the two ports. Refer to Truth Table IV for more details. When changing the bank assignments, accesses of the affected banks must be suspended. Accesses may continue uninterrupted in banks that are not being reallocated. 3. Generated upon mailbox access. 4. All Vcc pins must be connected to power supply. 5. All GND pins must be connected to ground supply. 6. The first six address pins (A0-A5) for each port serve dual functions. When MBSEL = VIH, the pins serve as memory address inputs. When MBSEL = VIL, the pins serve as mailbox address inputs (A6-A13 ignored).
3 6.42
IDT70V7288S/L 64K x 16 3.3V Bank-Switchable Dual-Ported SRAM with External Bank Selects
Industrial and Commercial Temperature Ranges
Truth Table I – Chip
CE CE0 V IL L < 0.2V VIH H X >V CC -0.2V X
Enable(1,2,3,4)
CE1 VIH >VCC -0.2V X V IL X VCC - 0.2V VIN > VCC - 0.2V or IND VIN < 0.2V, f = 0(4) MBSELR = MBSELL > VCC - 0.2V COM'L CE"A" < 0.2V and CE"B" > VCC - 0.2V(5) MBSELR = MBSELL > VCC - 0.2V IND VIN > VCC - 0.2V or V IN < 0.2V Active Port Outputs Disabled (3) f = fMAX
S L
1.5 1.5
6 3
1.5 1.5
6 3
1.5 1.5
mA
S L
____ ____
____ ____
____ ____
____ ____
1.5 1.5 85 85 85 85
ISB4
Full Standby Current (One Port - All CMOS Level Inputs)
S L
115 115
____ ____
140 125
____ ____
95 95
130 110
____ ____
mA
S L
____ ____
6.42 6
IDT70V7288S/L 64K x 16 3.3V Bank-Switchable Dual-Ported SRAM with External Bank Selects
Industrial and Commercial Temperature Ranges
3.3V 3.3V 590Ω DATAOUT
AC Test Conditions
Input Pulse Levels Input Rise/Fall Times Input Timing Reference Levels Output Reference Levels Output Load GND to 3.0V 3ns Max. 1.5V 1.5V Figures 1,2 and 3
4077 tbl 11
590Ω DATAOUT INT 435Ω 30pF
435Ω
5pF*
4077 drw 03
, 4077 drw 04
Figure 1. AC Output Test Load
8 7 6 5 ∆ tACE/tAA (Typical, ns) 4 3 2 1
- 10pF is the I/O capacitance of this device, and 30pF is the AC Test Load Capacitance
Figure 2. Output Test Load (for tLZ, tHZ, tWZ, tOW) *Including scope and jig.
AC Electrical Characteristics Over the Operating Temperature and Supply Voltage Range(4)
70V7288X15 Com'l Only Symbol Parameter Min. Max.
READ CYCLE tRC tAA
tACE
tABE
tAOE tOH tLZ tHZ tPU tPD
D E DS NN EG M SI ME OD C EW RE TN O N
0 -1 20 40 60 80 100 120 140 160 180 200 Capacitance (pF)
, 4077 drw 05
R O F
Figure 3. Lumped Capacitance Load Typical Derating Curve
70V7288X20 Com'l Only
70V7288X25 Com'l & Ind Min. Max. Unit
Min.
Max.
Read Cycle Time
15
____
20
____
25
____ ____
____
ns ns ns ns ns ns ns ns ns ns ns ns
4077 tbl 12
Address Access Time
____ ____
15 15 15 9
____ ____
20 20 20
25 25 25 11
____
Chip Enable Access Time Byte Enable Access Time
(3) (3)
____
____
____
Output Enable Access Time
____
____
10
____
Output Hold from Address Change Output Low-Z Time
(1,2) (1,2) (2,5)
3
____
3 0
____
3 0
____
0
____
____
____
____
Output High-Z Time
8
____
____
9
____
10
____
Chip Enab le to Power Up Time
0
(2,5)
____
0
____
0
____
Chip Disable to Power Down Time
15
____
20
____
25
____
tMOP tMAA
Mailbox Flag Update Pulse (OE or MBSEL) Mailbox Address Access Time
10
____
10
____
10
____
15
20
25
NOTES: 1. Transition is measured 0mV from Low or High-impedance voltage with Output Test Load (Figure 2). 2. This parameter is guaranteed by device characterization, but is not production tested. 3. To access RAM, CE = VIL and MBSEL = VIH. To access mailbox, CE= VIH and MBSEL = VIL. 4. 'X' in part numbers indicates power rating (S or L). 5. Refer to Truth Table I.
7 6.42
IDT70V7288S/L 64K x 16 3.3V Bank-Switchable Dual-Ported SRAM with External Bank Selects
Industrial and Commercial Temperature Ranges
Assigning the Banks via the External Bank Selects
There are four bank select pins available on the IDT70V7288, and each of these pins is associated with a specific bank within the memory array. The pins are user-controlled inputs: access to a specific bank is assigned to a particular port by setting the input to the appropriate level. The process of assigning the banks is detailed in Truth Table IV. Once a bank is assigned to a port, the owning port has full access to read and write within that bank. The opposite port is unable to access that bank until the user reassigns the port. Access by a port to a bank which it does not control will have no effect if written, and if read unknown values on D0-D15 will be returned. Each port can be assigned as many banks within the array as needed, up to and including all four banks. The bank select pin inputs must be set at either VIH or VIL - these inputs are not tri-statable. When changing the bank assignments, accesses of the affected banks must be suspended. Accesses may continue uninterrupted in banks that are not being reallocated.
Truth Table IV – Memory Bank Assignment (CE = VIH)(2,3)
BKSEL0 H BKSEL1 X BKSEL2 X X BKSEL3 X X X BANK AND DIRECTION(1) BANK 0 LEFT BANK 1 LEFT
NOTES: 4077 tbl 13 1. Bank 0 refers to the first 16Kx16 memory spaces, Bank 1 to the second 16Kx16 memory spaces, Bank 2 to the third 16Kx16 memory spaces; and Bank 3 to the fourth 16Kx16 memory spaces. 'LEFT' indicates the bank is assigned to the left port; 'RIGHT' indicates the bank is assigned to the right port. 0-4 banks may be assigned to either port. 2. The bank select pin inputs must be set at either VIH or V IL - these inputs are not tristatable. When changing the bank assignments, accesses of the affected banks must be suspended. Accesses may continue uninterrupted in banks that are not being reallocated. 3. 'H' = VIH, 'L' = VIL, 'X' = Don't Care.
Mailbox Interrupts and Interrupt Control Registers
If the user chooses the mailbox interrupt function, four mailbox locations are assigned to each port. These mailbox locations are external to the memory array. The mailboxes are accessed by taking MBSEL LOW while holding CE HIGH. The mailboxes are 16 bits wide and controllable by byte: the message is user-defined since these are addressable SRAM locations. An interrupt is generated to the opposite port upon writing to the upper byte of any mailbox location. A port can read the message it has just written in order to verify it: this read will not alter the status of the interrupt sent to the opposite port. The interrupted port can clear the interrupt by reading the upper byte of the applicable mailbox. This read will not alter the contents of the mailbox. The use of mailboxes to generate interrupts to the opposite port and the reading of mailboxes to clear interrupts is detailed in Truth Table V. If desired, any of the mailbox interrupts can be independently
D E DS NN EG M SI ME OD C EW RE TN O N
X H X X L X X H BANK 2 LEFT BANK 3 LEFT X X X L H X L X X X L BANK 0 RIGHT BANK 1 RIGHT BANK 2 RIGHT X X X X X X BANK 3 RIGHT
R O F
masked via software. Masking of the interrupt sources is done in the Mask Register. The masks are individual and independent: a port can mask any combination of interrupt sources with no effect on the other sources. Each port can modify only its own Mask Register. The use of this register is detailed in Truth Table V. Two registers are provided to permit interpretation of interrupts: these are the Interrupt Cause Register and the Interrupt Status Register. The Interrupt Cause Register gives the user a snapshot of what has caused the interrupt to be generated - the specific mailbox written to by the opposite port. The information in this register provides post-mask signals: interrupt sources that have been masked will not be updated. The Interrupt Status Register gives the user the status of all bits that could potentially cause an interrupt regardless of whether they have been masked. The use of the Interrupt Cause Register and the Interrupt Status Register is detailed in Truth Table V.
6.42 8
IDT70V7288S/L 64K x 16 3.3V Bank-Switchable Dual-Ported SRAM with External Bank Selects
Industrial and Commercial Temperature Ranges
Truth Table V – Mailbox Interrupts (CE = VIH)(8,9)
MB SEL L L L L L L ↓ ↓ ↓ ↓ L L L R/ W X X (1) (1) (1) (1) H H H H (3) X X UB X X (1) (1) (1) (1) (2) (2) (2) (2) (3) X X LB X X (1) (1) (1) (1) (2) (2) (2) (2) (3) X X A5 L
• • •
A4 L
• • •
A3 L
• • •
A2 L
• • •
A1 L
• • •
A0 L
• • •
D0
D1
D2
D3
D4
D5
D6
D7
D8
D9
D10
D11
D12
D13
D14
D15
DESCRIPTION RESERVED (7) RESERVED (7)
RESERVED (7) RESERVED (7) X X X X X X X X (4) X X X X X X X X (4) X X X X X X X X (4) X X X X X X X X (4) X X X X X X X X (5) X X X X X X X X (5) X X X X X X X X (5) X X X X X X X X (5) X X X X X X X X (6) X X X X X X X X (6) X X X X X X X X (6) X X X X X X X X (6) X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X
H H H H H H H H H
• • •
L L L L L L L L L
• • •
L L L L L L L L H
• • •
L L L L H H H H L
• • •
L L H H L L H H L
• • •
L H L H L H L H L
• • •
MAILBOX 0 - SET INTERRUPT ON OPPOSITE PORT MAILBOX 1 - SET INTERRUPT ON OPPOSITE PORT MAILBOX 2 - SET INTERRUPT ON OPPOSITE PORT MAILBOX 3 - SET INTERRUPT ON OPPOSITE PORT MAILBOX 0 - CLEAR OPPOSITE PORT INTERRUPT MAILBOX 1 - CLEAR OPPOSITE PORT INTERRUPT MAILBOX 2 - CLEAR OPPOSITE PORT INTERRUPT MAILBOX 3 - CLEAR OPPOSITE PORT INTERRUPT MAILBOX INTERRUPT CONTROLS RESERVED (7) RESERVED (7)
RESERVED (7) RESERVED (7)
H
H
H
H
H
H
NOTES: 1. There are four independent mailbox locations available to each side, external to the standard memory array. The mailboxes can be written to in either 8-bit or 16-bit widths. The upper byte of each mailbox has an associated interrupt to the opposite port. The mailbox interrupts can be individually masked if desired, and the status of the interrupt determined by polling the Interrupt Status Register (see Note 6 for this table). A port can read its own mailboxes to verify the data written, without affecting the interrupt which is sent to the opposite port. 2. These registers allow a port to read the data written to a specific mailbox location by the opposite port. Reading the upper byte of the data in a particular mailbox clears the interrupt associated with that mailbox without modifying the data written. Once the address and R/W are stable, the actual clearing of the interrupt is triggered by the transition of MBSEL from VIH to VIL. 3. This register contains the Mask Register (bits D0-D3), the Interrupt Cause Register (bits D4-D7), and the Interrupt Status Register (bits D8-D11). The controls for R/W, UB, and LB are manipulated in accordance with the appropriate function. See Notes 4, 5, and 6 for this table. Bits D12-D15 are "Don't Care". 4. This register, the Mask Register, allows the user to independently mask the various interrupt sources. Writing VIH to the appropriate bit (D0 = Mailbox 0, D1 = Mailbox 1, D2 = Mailbox 2, and D 3 = Mailbox 3) disables the interrupt, while writing VIL enables the interrupt. All four bits in this register must be written at the same time. This register can be read at any time to verify the mask settings. The masks are individual and independent: any single interrupt source can be masked with no effect on the other sources. Each port can modify only its own mask settings. 5. This register, the Interrupt Cause Register, gives the user a snapshot of what has caused the interrupt to be generated. Reading VOL for a specific bit (D4 = Mailbox 0, D5 = Mailbox 1, D6 = Mailbox 2, and D7 = Mailbox 3) indicates that the associated interrupt source has generated an interrupt. Acknowledging the interrupt clears the bit in this register (see Note 2 for this table). This register provides post-mask information: if the interrupt source has been masked, the associated bit in this register will not update. 6. This register, the Interrupt Status Register, gives the user the status of all interrupt sources that could potentially cause an interrupt regardless of whether they have been masked. Reading VOL for a specific bit (D8 = Mailbox 0, D9 = Mailbox 1, D10 = Mailbox 2, and D11 = Mailbox 3) indicates that the associated interrupt source has generated an interrupt. Acknowledging the interrupt clears the associated bit in this register (see Note 2 for this table). This register provides pre-mask information: regardless of whether an interrupt source has been masked, the associated bit in this register will update. 7. Access to registers defined as "RESERVED" will have no effect, if written, and if read unknown values on D0-D15 will be returned. 8. These registers are not guaranteed to initialize in any known state. At power-up, the initialization sequence should include the set-up of these registers. 9. 'L' = VIL or VOL, 'H' = VIH or V OH, 'X' = Don't Care.
D E DS NN EG M SI ME OD C EW RE TN O N
R O F
4077 tbl 14
9 6.42
IDT70V7288S/L 64K x 16 3.3V Bank-Switchable Dual-Ported SRAM with External Bank Selects
Industrial and Commercial Temperature Ranges
Waveform of Read
Cycles(4)
tRC
ADDR tAA tACE (3) tAOE OE tABE (3) UB, LB
(3) (3)
CE
(5)
DATAOUT
NOTES: 1. Timing depends on which signal is asserted last, CE, OE, LB, or UB. 2. Timing depends on which signal is de-asserted first CE, OE, LB, or UB. 3. Start of valid data depends on which timing becomes effective last: tAOE, tACE, tAA or tABE. 4. MBSEL = VIH. 5. Refer to Truth Table I.
Timing of Power-Up Power-Down
CE (5)
D E DS NN EG M SI ME OD C EW RE TN O N
R/W tLZ (1) tOH VALID DATA
(3)
R O F
4077 drw 06
tHZ
(2)
ICC ISB
tPU
tPD
50%
50%
4077 drw 07
,
610 .42
IDT70V7288S/L 64K x 16 3.3V Bank-Switchable Dual-Ported SRAM with External Bank Selects
Industrial and Commercial Temperature Ranges
AC Electrical Characteristics Over the Operating Temperature and Supply Voltage(5)
70V7288X15 Com'l Only Symbol WRITE CYCLE tWC tEW tAW tAS tBS tWP Write Cycle Time Chip Enable to End-of-Write (3) Address Valid to End-of-Write Address Set-up Time Bank Set-up Time Write Pulse Width
(3)
70V7288X20 Com'l Only Min. Max.
70V7288X25 Com'l & Ind Min. Max. Unit
Parameter
Min.
Max.
15 12 12 0 0 12 0
____
20 15 15 0 0 15 0
____
25 20 20 0 0 20 0
____
ns ns ns ns ns ns ns ns
____
____
____
____
____
____
____
____
____
____ ____
____ ____
tWR
tDW tHZ tDH
tWZ
tOW
tMWRD
NOTES: 1. Transition is measured 0mV from Low or High-impedance voltage with Output Test Load (Figure 2). 2. This parameter is guaranteed by device characterization, but is not production tested. 3. To access RAM,CE = VIL and MBSEL = VIH. To access mailbox, CE = VIH and MBSEL = VIL. Either condition must be valid for the entire tEW time. Refer to Truth Tables I and III. 4. The specification for t DH must be met by the device supplying write data to the RAM under all operating conditions. Although tDH and tOW values will vary over voltage and temperature, the actual tDH will always be smaller than the actual tOW. 5. 'X' in part numbers indicates power rating (S or L).
D E DS NN EG M SI ME OD C EW RE TN O N
Write Recovery Time Data Valid to End-of-Write Output High-Z Time (1,2) Data Hold Time
(4)
12
____
15
____
20
R O F
____ ____ ____ ____ ____ ____
____
8
____
9
____
10
____
ns ns ns ns ns
4077 tbl 15
0
____
0
____
0
Write Enab le to Output in High-Z(1,2)
____
8
____
9
____
10
____
Output Active from End-of-Write (1,2,4) Mailbo x Write to Read Time
3
____
3 5
____
3 5
5
____
____
____
611 .42
IDT70V7288S/L 64K x 16 3.3V Bank-Switchable Dual-Ported SRAM with External Bank Selects
Industrial and Commercial Temperature Ranges
Timing Waveform of Write Cycle No. 1, R/W Controlled Timing(1,5,8)
tWC ADDRESS tHZ OE tAW CE or MBSEL UB or LB
(9,10) (7)
(9) (2) (3)
tAS (6) R/W tLZ
tWP
tWR
DATAOUT
DATAIN
Timing Waveform of Write Cycle No. 2, CE, UB, LB Controlled Timing(1,5)
tWC
ADDRESS
CE or MBSEL
D E DS NN EG M SI ME OD C EW RE TN O N
tWZ (7) tOW VALID (4) tDW tDH
tAW
(9,10)
R O F
(4) 4077 drw 08
tAS
(6)
tEW (2)
tWR(3)
UB or LB
(9)
R/W
tDW
tDH
DATAIN
4077 drw 09
NOTES: 1. R/W or CE or UB and LB must be HIGH during all address transitions. 2. A write occurs during the overlap (tEW or tWP) of a LOW CE and a LOW R/W for memory array writing cycle. 3. tWR is measured from the earlier of CE or R/W (or MBSEL or R/W) going HIGH to the end of write cycle. 4. During this period, the I/O pins are in the output state and input signals must not be applied. 5. If the CE or MBSEL LOW transition occurs simultaneously with or after the R/W LOW transition, the outputs remain in the High-impedance state. 6. Timing depends on which enable signal is asserted last, CE or R/W. 7. This parameter is guaranteed by device characterization, but is not production tested. Transition is measured 0mV from steady state with the Output Test Load (Figure 2). 8. If OE is LOW during R/W controlled write cycle, the write pulse width must be the larger of tWP or (tWZ + tDW) to allow the I/O drivers to turn off and data to be placed on the bus for the required tDW. 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 tWP. 9. To access RAM, CE = VIL and MBSEL = VIH. To access mailboxes, CE = VIH and MBSEL = VIL. tEW must be met for either condition. 10. Refer to Truth Table I.
612 .42
IDT70V7288S/L 64K x 16 3.3V Bank-Switchable Dual-Ported SRAM with External Bank Selects
Industrial and Commercial Temperature Ranges
Timing Waveform of Left Port Write to Right Port Read of Same Data(1,2,3)
tWC A0L-13L and A0R-13R tAW CEL tEW tWR ADDRESSES MATCH
CER tBS BKSEL0-3 tAS R/WL tDW tDH tWP
tACE
NOTES: 1. UB and LB are controlled as necessary to enable the desired byte accesses. 2. Timing for Right Port Write to Left Port Read is identical. 3. Refer to Truth Tables I and IV.
Timing Waveform of Mailbox Read after Write Timing, Either Side(1,2)
tMAA tOH A0-A5 VALID ADDRESS tAW tEW VALID ADDRESS tACE
D E DS NN EG M SI ME OD C EW RE TN O N
I/O0L-15L DATAIN VALID R/WR OER I/O0R-15R tLZ tOH DATAOUT VALID
Write Cycle Read Cycle
R O F
tHZ
4077 drw 10
tWR
MBSEL
tMOP
I/O0-15 tAS R/W tWP
tDW DATAIN VALID tDH
DATAOUT VALID
tMWRD OE
Write Cycle Read Cycle
tAOE
NOTES: 1. CE = VIH for the duration of the above timing (both write and read cycle), refer to Truth Table I. 2. UB and LB are controlled as necessary to enable the desired byte accesses.
4077 drw 11
613 .42
IDT70V7288S/L 64K x 16 3.3V Bank-Switchable Dual-Ported SRAM with External Bank Selects
Industrial and Commercial Temperature Ranges
AC Electrical Characteristics Over the Operating Temperature and Supply Voltage Range(1)
70V7288X15 Com'l Only Symbol INTERRUPT TIMING tAS tWR tINS tINR Address Set-up Time Write Recovery Time Interrupt Set Time Interrupt Reset Time 0 0
____ ____ ____
70V7288X20 Com'l Only Min. Max.
70V7288X25 Com'l & Ind Min. Max. Unit
Parameter
Min.
Max.
0 0
____ ____
____
0 0
____ ____
____
ns ns ns ns
____
____
____
15 15
20 20
NOTES: 1. 'X' in part numbers indicates power rating (S or L).
Waveform of Interrupt Timing
ADDR"A"
MBSEL"A"
ADDR"B"
MBSEL"B"
D E DS NN EG M SI ME OD C EW RE TN O N
(1,5)
tWC MAILBOX SET ADDRESS
(2)
R O F
25 25
4077 tbl 16
tAS
(3)
tWR (4)
R/W"A"
tINS(3)
INT"B"
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tRC
MAILBOX CLEAR ADDRESS
(2)
tAS
(3)
OE"B" tINR(3) INT"B"
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NOTES: 1. All timing is the same for left and right ports. Port “A” may be either the left or right port. Port “B” is the port opposite from port “A”. 2. See Interrupt Truth Table V. 3. Timing depends on which enable signal ( CE or R/W) is asserted last. 4. Timing depends on which enable signal ( CE or R/W) is de-asserted first. 5. Refer to Truth Tables I.
614 .42
IDT70V7288S/L 64K x 16 3.3V Bank-Switchable Dual-Ported SRAM with External Bank Selects
Industrial and Commercial Temperature Ranges
Depth and Width Expansion
The IDT70V7288 features dual chip enables (refer to Truth Table I) in order to facilitate rapid and simple depth expansion with no requirements for external logic. Figure 4 illustrates how to control the various chip enables in order to expand two devices in depth. The IDT70V7288 can also be used in applications requiring expanded width, as indicated in Figure 4. Since the banks are allocated at the discretion of the user, the external controller can be set up to drive the input signals for the various devices as required to allow for 32-bit or wider applications.
A14(1)
IDT70V7288 Bank-Switchable SRAM
CE0 CE1 VCC
IDT70V7288 Bank-Switchable SRAM
CE0 CE1 VCC
NOTE: 1. This signal is provided by external logic. It is not a bit present on the address bus.
D E DS NN EG M SI ME OD C EW RE TN O N
Control Inputs Control Inputs
IDT70V7288 Bank-Switchable SRAM
R O F
,
CE1 CE0
IDT70V7288 Bank-Switchable SRAM
CE1 CE0
Control Inputs
Control Inputs
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BKSEL0-3 R/W LB, UB OE
Figure 4. Depth and Width Expansion with IDT70V7288
615 .42
IDT70V7288S/L 64K x 16 3.3V Bank-Switchable Dual-Ported SRAM with External Bank Selects
Industrial and Commercial Temperature Ranges
Ordering Information
IDT XXXXX Device Type A Power 999 Speed A Package A Process/ Temperature Range Blank I Commercial (0°C to +70°C) Industrial (-40°C to +85°C)
PF
100-pin TQFP (PN100-1)
Datasheet Document History
3/8/99:
6/11/99: 9/1/99: 3/10/00:
D E DS NN EG M SI ME OD C EW RE TN O N
15 20 25 Commercial Only Commercial & Industrial Commercial & Industrial S L Standard Power Low Power 70V7288
R O F
,
Speed in nanoseconds
1Mbit (4 x 16K x 16) 3.3V Bank-Switchable Dual-Ported SRAM with External Bank Selects
4077 drw 15
6/8/00:
Initiated datasheet document history Converted to new format Cosmetic typographical corrections Page 3 Added additional notes to pin configurations Added 15ns speed grade Changed drawing format Removed Preliminary Added Industrial Temperature Ranges and removed corresponding notes Replaced IDT logo Page 1 Added industrial temperature note Changed ±200mV to 0mV in notes Page 5 Increated storage temperature parameter Clarified TA Parameter Page 6 DC Electrical parameters–changed wording from "open" to "disabled"
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616 .42