IS61QDPB41M18A Datasheet, PDF (23/33 Pages) Integrated Silicon Solution, Inc – 512Kx36 and 1Mx18 configuration available

IS61QDPB41M18A/A1/A2
IS61QDPB451236A/A1/A2
IEEE 1149.1 Serial Boundary Scan of JTAG
These SRAMs incorporate a serial boundary scan Test Access Port (TAP) controller in 165 FBGA package. That is
fully compliant with IEEE Standard 1149.1-2001. The TAP controller operates using standard 1.8 V interface logic
levels.
Disabling the JTAG feature
These SRAMs operate 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 internally pulled up and may be unconnected. They may alternatively
be connected to VDD through a pull up resistor. TDO must be left unconnected. Upon power up, the device comes up
in a reset state, which does not interfere with the operation of the device.
Test Access Port Signal List:
Test Clock (TCK)
The test clock is to operate only 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 (TMS)
The TMS input is to set commands of the TAP controller and is sampled on the rising edge of TCK. This pin can be left
unconnected at SRAM operation. The pin is pulled up internally to keep logic high level.
Test Data-In (TDI)
The TDI pin is to receive serially input information into the instruction and data registers. It 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 (Refer to the TAP Controller State
Diagram). TDI is internally pulled up and can be unconnected at SRAM. TDI is connected to the most significant bit
(MSB) on any register.
Test Data-Out (TDO)
The TDO pin is to drive serially clock data out from the JTAG registers. The output is active, depending upon the
current state of the TAP state machine (Refer to instruction codes). The output changes on the falling edge of TCK.
TDO is connected to the least significant bit (LSB) of any register.
Integrated Silicon Solution, Inc.- www.issi.com
Rev. B
23
10/02/2014