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CY7C1298H
1-Mbit (64K x 18) Pipelined DCD Sync SRAM
Features
• Registered inputs and outputs for pipelined operation • Optimal for performance (Double-Cycle deselect) — Depth expansion without wait state • 64K × 18-bit common I/O architecture • 3.3V core power supply (VDD) • 2.5V/3.3V I/O power supply (VDDQ) • Fast clock-to-output times — 3.5 ns (for 166-MHz device) • Provide high-performance 3-1-1-1 access rate • User-selectable burst counter supporting Intel® Pentium® interleaved or linear burst sequences • Separate processor and controller address strobes • Synchronous self-timed writes • Asynchronous Output Enable • Available in JEDEC-standard lead-free 100-Pin TQFP package • “ZZ” Sleep Mode option
Functional Description[1]
The CY7C1298H SRAM integrates 64K x 18 SRAM cells with advanced synchronous peripheral circuitry and a two-bit counter for internal burst operation. All synchronous inputs are gated by registers controlled by a positive-edge-triggered Clock Input (CLK). The synchronous inputs include all addresses, all data inputs, address-pipelining Chip Enable (CE1), depth-expansion Chip Enables (CE2 and CE3), Burst Control inputs (ADSC, ADSP, and ADV), Write Enables (BW[A:B], and BWE), and Global Write (GW). Asynchronous inputs include the Output Enable (OE) and the ZZ pin. Addresses and chip enables are registered at rising edge of clock when either Address Strobe Processor (ADSP) or Address Strobe Controller (ADSC) are active. Subsequent burst addresses can be internally generated as controlled by the Advance pin (ADV). Address, data inputs, and write controls are registered on-chip to initiate a self-timed Write cycle.This part supports Byte Write operations (see Pin Descriptions and Truth Table for further details). Write cycles can be one to two bytes wide as controlled by the byte write control inputs. GW active LOW causes all bytes to be written. This device incorporates an additional pipelined enable register which delays turning off the output buffers an additional cycle when a deselect is executed.This feature allows depth expansion without penalizing system performance. The CY7C1298H operates from a +3.3V core power supply while all outputs operate either with a +2.5V or +3.3V supply. All inputs and outputs are JEDEC-standard JESD8-5-compatible.
Selection Guide
166 MHz Maximum Access Time Maximum Operating Current Maximum CMOS Standby Current 3.5 240 40 133 MHz 4.0 225 40 Unit ns mA mA
Note: 1. For best-practices recommendations, please refer to the Cypress application note System Design Guidelines on www.cypress.com.
Cypress Semiconductor Corporation Document #: 38-05665 Rev. *B
•
198 Champion Court
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San Jose, CA 95134-1709 • 408-943-2600 Revised July 5, 2006
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CY7C1298H
Functional Block Diagram
ADDRESS REGISTER
2 A[1:0]
Q1 BURST COUNTER AND LOGIC CLR Q0
A0, A1, A
MODE ADV CLK
ADSC ADSP DQB, DQPB BYTE WRITE REGISTER DQA , DQPA BYTE WRITE REGISTER ENABLE REGISTER DQB , DQPB BYTE WRITE DRIVER DQA, DQPA BYTE WRITE DRIVER MEMORY ARRAY SENSE AMPS
BWB
OUTPUT REGISTERS
OUTPUT BUFFERS
E
DQs, DQPA DQPB
BWA BWE GW CE1 CE2 CE3 OE
PIPELINED ENABLE
INPUT REGISTERS
ZZ
SLEEP CONTROL
Document #: 38-05665 Rev. *B
Page 2 of 16
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CY7C1298H
Pin Configurations 100-Pin TQFP
Top View CE1 CE2 NC NC BWB BWA CE3 VDD VSS CLK GW BWE OE ADSC ADSP ADV A A 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 51
VDDQ VSSQ NC NC DQB DQB VSSQ VDDQ DQB DQB NC VDD NC VSS DQB DQB VDDQ VSSQ DQB DQB DQPB NC VSSQ VDDQ NC NC NC
NC NC NC
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
100 99 98 97 96 95 94 93 92 91 90 89 88 87 86 85 84 83 82 81
A A
CY7C1298H
A NC NC VDDQ VSSQ NC DQPA DQA DQA VSSQ VDDQ DQA DQA VSS NC VDD ZZ DQA DQA VDDQ VSSQ DQA DQA NC NC VSSQ VDDQ NC NC NC
MODE A A A A A1 A0
NC/72M NC/36M VSS VDD
NC/18M NC/9M
Document #: 38-05665 Rev. *B
A A A A NC/2M NC/4M
A
31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
Page 3 of 16
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CY7C1298H
Pin Descriptions
Pin A0, A1, A Type Description InputAddress Inputs used to select one of the 64K address locations. Sampled at the rising edge Synchronous of the CLK if ADSP or ADSC is active LOW, and CE1, CE2, and CE3 are sampled active. A[1:0] are fed to the two-bit counter. InputByte Write Select Inputs, active LOW. Qualified with BWE to conduct byte writes to the SRAM. Synchronous Sampled on the rising edge of CLK. InputGlobal Write Enable Input, active LOW. When asserted LOW on the rising edge of CLK, a global Synchronous write is conducted (ALL bytes are written, regardless of the values on BW[A:B] and BWE). InputByte Write Enable Input, active LOW. Sampled on the rising edge of CLK. This signal must be Synchronous asserted LOW to conduct a byte write. InputClock Clock Input. Used to capture all synchronous inputs to the device. Also used to increment the burst counter when ADV is asserted LOW, during a burst operation.
BW[A:B] GW BWE CLK CE1
InputChip Enable 1 Input, active LOW. Sampled on the rising edge of CLK. Used in conjunction with Synchronous CE2 and CE3 to select/deselect the device. ADSP is ignored if CE1 is HIGH. CE1 is sampled only when a new external address is loaded. InputChip Enable 2 Input, active HIGH. Sampled on the rising edge of CLK. Used in conjunction with Synchronous CE1 and CE3 to select/deselect the device. CE2 is sampled only when a new external address is loaded. InputChip Enable 3 Input, active LOW. Sampled on the rising edge of CLK. Used in conjunction with Synchronous CE1 and CE2 to select/deselect the device. CE3 is sampled only when a new external address is loaded. InputOutput Enable, asynchronous input, active LOW. Controls the direction of the I/O pins. When Asynchronous LOW, the I/O pins behave as outputs. When deasserted HIGH, I/O pins are tri-stated, and act as input data pins. OE is masked during the first clock of a read cycle when emerging from a deselected state. InputAdvance Input signal, sampled on the rising edge of CLK, active LOW. When asserted, it Synchronous automatically increments the address in a burst cycle. InputAddress Strobe from Processor, sampled on the rising edge of CLK, active LOW. When Synchronous asserted LOW, addresses presented to the device are captured in the address registers. A[1:0] are also loaded into the burst counter. When ADSP and ADSC are both asserted, only ADSP is recognized. ASDP is ignored when CE1 is deasserted HIGH. InputAddress Strobe from Controller, sampled on the rising edge of CLK, active LOW. When Synchronous asserted LOW, addresses presented to the device are captured in the address registers. A[1:0] are also loaded into the burst counter. When ADSP and ADSC are both asserted, only ADSP is recognized. InputZZ “sleep” Input, active HIGH. When asserted HIGH places the device in a non-time-critical Asynchronous “sleep” condition with data integrity preserved. For normal operation, this pin has to be LOW or left floating. The ZZ pin has an internal pull-down. I/OBidirectional Data I/O lines. As inputs, they feed into an on-chip data register that is triggered by Synchronous the rising edge of CLK. As outputs, they deliver the data contained in the memory location specified by the addresses presented during the previous clock rise of the read cycle. The direction of the pins is controlled by OE. When OE is asserted LOW, the pins behave as outputs. When HIGH, DQs and DQP[A:B] are placed in a tri-state condition. Power Supply Power supply inputs to the core of the device. Ground I/O Power Supply I/O Ground InputStatic Ground for the core of the device. Power supply for the I/O circuitry. Ground for the I/O circuitry. Selects Burst Order. When tied to GND selects linear burst sequence. When tied to VDD or left floating selects interleaved burst sequence. This is a strap pin and should remain static during device operation. Mode Pin has an internal pull-up. No Connects. Not internally connected to the die. 2M, 4M, 9M, 18M, 72M, 144M, 288M, 576M and 1G are address expansion pins and are not internally connected to the die. Page 4 of 16
CE2
CE3
OE
ADV ADSP
ADSC
ZZ
DQs DQP[A:B]
VDD VSS VDDQ VSSQ MODE
NC
Document #: 38-05665 Rev. *B
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CY7C1298H
Functional Overview
All synchronous inputs pass through input registers controlled by the rising edge of the clock. All data outputs pass through output registers controlled by the rising edge of the clock. The CY7C1298H supports secondary cache in systems utilizing either a linear or interleaved burst sequence. The interleaved burst order supports Pentium and i486‰ processors. The linear burst sequence is suited for processors that utilize a linear burst sequence. The burst order is user selectable, and is determined by sampling the MODE input. Accesses can be initiated with either the Processor Address Strobe (ADSP) or the Controller Address Strobe (ADSC). Address advancement through the burst sequence is controlled by the ADV input. A two-bit on-chip wraparound burst counter captures the first address in a burst sequence and automatically increments the address for the rest of the burst access. Byte write operations are qualified with the Byte Write Enable (BWE) and Byte Write Select (BW[A:B]) inputs. A Global Write Enable (GW) overrides all byte write inputs and writes data to all four bytes. All writes are simplified with on-chip synchronous self-timed write circuitry. Synchronous Chip Selects CE1, CE2, CE3 and an asynchronous Output Enable (OE) provide for easy bank selection and output tri-state control. ADSP is ignored if CE1 is HIGH. Single Read Accesses This access is initiated when the following conditions are satisfied at clock rise: (1) ADSP or ADSC is asserted LOW, (2) chip selects are all asserted active, and (3) the write signals (GW, BWE) are all deasserted HIGH. ADSP is ignored if CE1 is HIGH. T
