Cypress CY7C1307BV25, CY7C1305BV25 manual Ieee 1149.1 Serial Boundary Scan Jtag

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CY7C1305BV25

CY7C1307BV25

IEEE 1149.1 Serial Boundary Scan (JTAG)

These SRAMs incorporate a serial boundary scan test access port (TAP) in the FBGA package. This part is fully compliant with IEEE Standard #1149.1-1900. The TAP operates using JEDEC standard 2.5V I/O logic levels.

Disabling the JTAG Feature

It is possible to operate the SRAM without using the JTAG feature. To disable the TAP controller, TCK must be tied LOW (VSS) to prevent clocking of the device. TDI and TMS are inter- nally pulled up and may be unconnected. They may alternately be connected to VDD through a pull-up resistor. TDO should be left unconnected. Upon power-up, the device will come up in a reset state which will not interfere with the operation of the device.

Test Access Port—Test Clock

The test clock is used only with the TAP controller. All inputs are captured on the rising edge of TCK. All outputs are driven from the falling edge of TCK.

Test Mode Select

The TMS input is used to give commands to the TAP controller and is sampled on the rising edge of TCK. It is allowable to leave this pin unconnected if the TAP is not used. The pin is pulled up internally, resulting in a logic HIGH level.

Test Data-In (TDI)

The TDI pin is used to serially input information into the registers and can be connected to the input of any of the registers. The register between TDI and TDO is chosen by the instruction that is loaded into the TAP instruction register. For information on loading the instruction register, see the TAP Controller State Diagram. TDI is internally pulled up and can be unconnected if the TAP is unused in an application. TDI is connected to the most significant bit (MSB) on any register.

Test Data-Out (TDO)

The TDO output pin is used to serially clock data-out from the registers. The output is active depending upon the current state of the TAP state machine (see Instruction codes). The output changes on the falling edge of TCK. TDO is connected to the least significant bit (LSB) of any register.

TDI and TDO pins as shown in TAP Controller Block Diagram. Upon power-up, the instruction register is loaded with the IDCODE instruction. It is also loaded with the IDCODE instruction if the controller is placed in a reset state as described in the previous section.

When the TAP controller is in the Capture IR state, the two least significant bits are loaded with a binary “01” pattern to allow for fault isolation of the board level serial test path.

Bypass Register

To save time when serially shifting data through registers, it is sometimes advantageous to skip certain chips. The bypass register is a single-bit register that can be placed between TDI and TDO pins. This allows data to be shifted through the SRAM with minimal delay. The bypass register is set LOW (VSS) when the BYPASS instruction is executed.

Boundary Scan Register

The boundary scan register is connected to all of the input and output pins on the SRAM. Several no connect (NC) pins are also included in the scan register to reserve pins for higher density devices.

The boundary scan register is loaded with the contents of the RAM Input and Output ring when the TAP controller is in the Capture-DR state and is then placed between the TDI and TDO pins when the controller is moved to the Shift-DR state. The EXTEST, SAMPLE/PRELOAD and SAMPLE Z instruc- tions can be used to capture the contents of the Input and Output ring.

The Boundary Scan Order tables show the order in which the bits are connected. Each bit corresponds to one of the bumps on the SRAM package. The MSB of the register is connected to TDI, and the LSB is connected to TDO.

Identification (ID) Register

The ID register is loaded with a vendor-specific, 32-bit code during the Capture-DR state when the IDCODE command is loaded in the instruction register. The IDCODE is hardwired into the SRAM and can be shifted out when the TAP controller is in the Shift-DR state. The ID register has a vendor code and other information described in the Identification Register Definitions table.

TAP Instruction Set

Performing a TAP Reset

A Reset is performed by forcing TMS HIGH (VDD) for five rising edges of TCK. This RESET does not affect the operation of the SRAM and may be performed while the SRAM is operating. At power-up, the TAP is reset internally to ensure that TDO comes up in a high-Z state.

TAP Registers

Registers are connected between the TDI and TDO pins and allow data to be scanned into and out of the SRAM test circuitry. Only one register can be selected at a time through the instruction registers. Data is serially loaded into the TDI pin on the rising edge of TCK. Data is output on the TDO pin on the falling edge of TCK.

Instruction Register

Three-bit instructions can be serially loaded into the instruction register. This register is loaded when it is placed between the

Eight different instructions are possible with the three-bit instruction register. All combinations are listed in the Instruction Code table. Three of these instructions are listed as RESERVED and should not be used. The other five instruc- tions are described in detail below.

Instructions are loaded into the TAP controller during the Shift-IR state when the instruction register is placed between TDI and TDO. During this state, instructions are shifted through the instruction register through the TDI and TDO pins. To execute the instruction once it is shifted in, the TAP controller needs to be moved into the Update-IR state.

IDCODE

The IDCODE instruction causes a vendor-specific, 32-bit code to be loaded into the instruction register. It also places the instruction register between the TDI and TDO pins and allows the IDCODE to be shifted out of the device when the TAP controller enters the Shift-DR state. The IDCODE instruction

Document #: 38-05630 Rev. *A

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Contents Configurations FeaturesFunctional Description CY7C1305BV25 1M x CY7C1307BV25 512K xLogic Block Diagram CY7C1307BV25 Logic Block Diagram CY7C1305BV25Selection Guide CY7C1305BV25-167 UnitCY7C1307BV25 512K x Pin\Configuration Ball Fbga 13 x 15 x 1.4 mm PinoutPin Definitions Introduction Application Example1 Operation Write Cycle Descriptions CY7C1305BV25 2Write Cycle Read CycleAre written into the device Write Cycle Descriptions CY7C1307BV25 2Operation Operation Document # 38-05630 Rev. *AIeee 1149.1 Serial Boundary Scan Jtag Sample Z EXIT2-IR UPDATE-DR UPDATE-IR TAP Controller State Diagram11Parameter Description Test Conditions Min Max Unit TAP Controller Block DiagramParameter Description Min Max Unit Set-up TimesIdentification Register Definitions TAP Timing and Test Conditions14Parameter Description Min Max Unit Output Times TCK Clock LOW to TDO ValidInstruction Codes Scan Register SizesRegister Name Bit Size Instruction Code DescriptionBit # Bump ID Boundary Scan OrderMaximum Ratings Operating RangeThermal Resistance22 AC Test Loads and Waveforms Capacitance22Parameter Description Test Conditions Max Unit Input Capacitance TA = 25C, f = 1 MHz VDD =Cycle Time Switching Characteristics Over the Operating Range23NOP Read Write Switching Waveforms27, 28Ordering Information Package DiagramCY7C1307BV25-167BZC CY7C1305BV25-167BZXC CY7C1307BV25-167BZI CY7C1305BV25-167BZXIDocument History Issue Date Orig. Description of ChangeSYT NXR

CY7C1307BV25, CY7C1305BV25 specifications

Cypress Semiconductor, a leader in embedded memory solutions, includes the CY7C1305BV25 and CY7C1307BV25 in its family of high-performance synchronous dynamic random-access memory (SDRAM) devices. These memory chips are designed for applications that require high-speed data processing and low power consumption, making them ideal for communication systems, networking devices, and other consumer electronics.

The CY7C1305BV25 is a 512K x 16-bit synchronous SRAM, while the CY7C1307BV25 offers a larger capacity of 1M x 16-bit. Both chips operate at a maximum clock frequency of 166 MHz, ensuring rapid data transfer rates and efficient memory operation. This high-speed performance is crucial in applications where quick data retrieval and storage are imperative.

One of the standout features of these devices is their ability to support a wide range of operating voltages, typically from 2.5V to 3.3V. This versatility allows them to be integrated into systems with varying power requirements, enhancing their adaptability for different designs. Additionally, the chips offer a low standby power consumption level, contributing to energy efficiency in battery-operated devices.

Both the CY7C1305BV25 and CY7C1307BV25 utilize a synchronous interface, allowing for coordinated data transfer with the system clock. This synchronization minimizes latency and improves overall system performance. The use of advanced pipelining techniques enables these devices to process multiple read and write commands concurrently, further boosting throughput.

In terms of reliability and durability, Cypress ensures that these memory chips comply with stringent industry standards. They are designed to withstand a wide temperature range, making them suitable for operation in diverse environments. The robust design includes features that mitigate the risk of data corruption and enhance data integrity, which is a vital consideration in mission-critical applications.

Overall, the CY7C1305BV25 and CY7C1307BV25 represent Cypress Semiconductor's commitment to delivering high-quality, high-performance memory solutions that meet the demanding requirements of modern electronics. Their impressive features, combined with a focus on low power consumption and reliability, make them a preferred choice for engineers and developers aiming to create the next generation of innovative products.
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