Cypress CY7C1166V18, CY7C1168V18, CY7C1177V18, CY7C1170V18 manual Idcode

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CY7C1166V18, CY7C1177V18 CY7C1168V18, CY7C1170V18

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 enables the IDCODE to be shifted out of the device when the TAP controller enters the Shift-DR state. The IDCODE instruction is loaded into the instruction register upon power up or whenever the TAP controller is supplied a test logic reset state.

SAMPLE Z

The SAMPLE Z instruction causes the boundary scan register to be connected between the TDI and TDO pins when the TAP controller is in a Shift-DR state. The SAMPLE Z command puts the output bus into a High-Z state until the next command is supplied during the Update IR state.

SAMPLE/PRELOAD

SAMPLE/PRELOAD is a 1149.1 mandatory instruction. When the SAMPLE/PRELOAD instructions are loaded into the instruc- tion register and the TAP controller is in the Capture-DR state, a snapshot of data on the inputs and output pins is captured in the boundary scan register.

The user must be aware that the TAP controller clock can only operate at a frequency up to 20 MHz, while the SRAM clock operates more than an order of magnitude faster. Because there is a large difference in the clock frequencies, it is possible that during the Capture-DR state, an input or output undergoes a transition. The TAP may then try to capture a signal while in transition (metastable state). This does not harm the device, but there is no guarantee as to the value that is captured. Repeatable results may not be possible.

To guarantee that the boundary scan register captures the cor- rect value of a signal, the SRAM signal must be stabilized long enough to meet the TAP controller's capture setup plus hold times (tCS and tCH). The SRAM clock input might not be captured correctly if there is no way in a design to stop (or slow) the clock during a SAMPLE/PRELOAD instruction. If this is an issue, it is still possible to capture all other signals and simply ignore the value of the CK and CK captured in the boundary scan register.

After the data is captured, it is possible to shift out the data by putting the TAP into the Shift-DR state. This places the boundary scan register between the TDI and TDO pins.

PRELOAD enables an initial data pattern to be placed at the latched parallel outputs of the boundary scan register cells be- fore the selection of another boundary scan test operation.

The shifting of data for the SAMPLE and PRELOAD phases can occur concurrently when required—that is, while data captured is shifted out, the preloaded data can be shifted in.

BYPASS

When the BYPASS instruction is loaded in the instruction register and the TAP is placed in a Shift-DR state, the bypass register is placed between the TDI and TDO pins. The advantage of the BYPASS instruction is that it shortens the boundary scan path when multiple devices are connected together on a board.

EXTEST

The EXTEST instruction enables the preloaded data to be driven out through the system output pins. This instruction also selects the boundary scan register to be connected for serial access between the TDI and TDO in the shift-DR controller state.

EXTEST Output Bus Tri-State

IEEE Standard 1149.1 mandates that the TAP controller is able to put the output bus into a tri-state mode.

The boundary scan register has a special bit located at bit #47. When this scan cell, called the “extest output bus tri-state”, is latched into the preload register during the Update-DR state in the TAP controller, it directly controls the state of the output (Q-bus) pins, when the EXTEST is entered as the current instruction. When HIGH, it enables the output buffers to drive the output bus. When LOW, this bit places the output bus into a High-Z condition.

Set this bit by entering the SAMPLE/PRELOAD or EXTEST command, and then shifting the desired bit into that cell, during the Shift-DR state. During Update-DR, the value loaded into that shift-register cell latches into the preload register. When the EXTEST instruction is entered, this bit directly controls the output Q-bus pins. Note that this bit is preset HIGH to enable the output when the device is powered up, and also when the TAP controller is in the Test-Logic-Reset state.

Reserved

These instructions are not implemented but are reserved for future use. Do not use these instructions.

Document Number: 001-06620 Rev. *D

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Contents Configurations FeaturesSelection Guide Functional Description Description 400 MHz 375 MHz 333 MHz 300 MHz UnitLogic Block Diagram CY7C1177V18 Logic Block Diagram CY7C1166V18Logic Block Diagram CY7C1170V18 Logic Block Diagram CY7C1168V18CY7C1166V18 2M x Pin ConfigurationsCY7C1177V18 2M x TMSCY7C1170V18 512K x CY7C1168V18 1M xBWS TMS TDIPin Name Pin Description Pin DefinitionsSynchronous Read/Write Input. When Negative Input Clock InputPower Supply Inputs for the Outputs of the Device Power Supply Inputs to the Core of the DeviceTDO for Jtag TCK Pin for JtagFunctional Overview SRAM#1 SRAM#2 Truth TableMaster OperationComments Write Cycle DescriptionsRemains unaltered During the Data portion of a write sequenceDevice Write cycle descriptions of CY7C1170V18 followsInto the device. D359 remains unaltered Device. D80 and D3518 remains unalteredIeee 1149.1 Serial Boundary Scan Jtag Idcode Shows the tap controller state diagram TAP Controller State DiagramTAP Electrical Characteristics TAP Controller Block DiagramTAP Controller Parameter Description Test Conditions Min Max UnitTAP Timing and Test Condition TAP AC Switching CharacteristicsScan Register Sizes Identification Register DefinitionsInstruction Codes Bit # Bump ID Boundary Scan OrderPower Up Sequence Power Up Sequence in DDR-II+ SramPower Up Waveforms DLL ConstraintsMaximum Ratings Electrical CharacteristicOperating Range AC Input RequirementsThermal Resistance CapacitanceAC Test Loads and Waveforms Parameter Description Test Conditions Max UnitHigh Parameter Min MaxLOW DLL TimingRead/Write/Deselect Sequence Switching WaveformNOP Ordering Information 333 Ball Fbga 13 x 15 x 1.4 mm Package DiagramDocument History ECN No Issue Date Orig. Description of ChangeNXR VKN/KKVTMP
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