CY7C1308DV25C-167BZC Cypress Semiconductor Corp, CY7C1308DV25C-167BZC Datasheet - Page 11

• Manufacturer Part Number: CY7C1308DV25C-167BZC
• Description: IC SRAM 9MBIT 167MHZ 165LFBGA
• Manufacturer: Cypress Semiconductor Corp

Specifications of CY7C1308DV25C-167BZC

• Format - Memory: RAM
• Memory Type: SRAM - Synchronous, DDR
• Memory Size: 9M (256K x 36)
• Speed: 167MHz
• Interface: Parallel
• Voltage - Supply: 2.4 V ~ 2.6 V
• Operating Temperature: 0°C ~ 70°C
• Package / Case: 165-LFBGA
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

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 is
loaded into the instruction register upon power-up or whenever
the TAP controller is given 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 given
during the “Update IR” state.
SAMPLE/PRELOAD
SAMPLE/PRELOAD is a 1149.1 mandatory instruction. When
the SAMPLE/PRELOAD instructions are loaded into the
instruction 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 10 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
correct value of a signal, the SRAM signal must be stabilized
long enough to meet the TAP controller's capture Setup plus hold
times (t
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.
Document #: 001-04310 Rev. *A
CS
and t
CH
). The SRAM clock input might not be captured
PRELIMINARY
PRELOAD allows an initial data pattern to be placed at the
latched parallel outputs of the boundary scan register cells prior
to 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 Three-state
IEEE Standard 1149.1 mandates that the TAP controller be able
to put the output bus into a three-state mode.
The boundary scan register has a special bit located at bit #47.
When this scan cell, called the “extest output bus three-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.
This bit can be set 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 pre-set 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.
CY7C1308DV25C
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