IS61NLF204836B Datasheet, PDF (24/38 Pages) Integrated Silicon Solution, Inc – 100 percent bus utilization

IS61NLF204836B/IS61NVF/NVVF204836B
IS61NLF409618B/IS61NVF/NVVF409618B 
IEEE 1149.1 SERIAL BOUNDARY SCAN (JTAG)
The serial boundary scan Test Access Port (TAP) is only
available in the PBGA package. (Not available in TQFP
package.) This port operates in accordance with IEEE
Standard 1149.1-1900, but does not include all functions
required for full 1149.1 compliance. These functions from
the IEEE specification are excluded because they place
added delay in the critical speed path of the SRAM. The
TAP controller operates in a manner that does not conflict
with the performance of other devices using 1149.1 fully
compliant TAPs.
DISABLING THE JTAG FEATURE
The SRAM can 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 disconnected. They may
alternately be connected to Vdd through a pull-up resistor.
TDO should be left disconnected. On power-up, the device
will start in a reset state which will not interfere with the
device operation.
TEST ACCESS PORT (TAP) - TEST CLOCK
The test clock is only used with the TAP controller. All inputs
are captured on the rising edge of TCK and outputs are
driven from the falling edge of TCK.
TEST MODE SELECT (TMS)
The TMS input is used to send commands to the TAP
controller and is sampled on the rising edge of TCK. This
pin may be left disconnected if the TAP is not used. The
pin is internally pulled up, resulting in a logic HIGH level.
TEST DATA-IN (TDI)
The TDI pin is used to serially input information to the
registers and can be connected to the input of any regis-
ter. The register between TDI and TDO is chosen by the
instruction loaded into the TAP instruction register. For
information on instruction register loading, see the TAP
Controller State Diagram. TDI is internally pulled up and
can be disconnected if the TAP is unused in an applica-
tion. TDI is connected to the Most Significant Bit (MSB)
on any register.
TAP CONTROLLER BLOCK DIAGRAM
0
Bypass Register
210
Instruction Register
TDI
Selection Circuitry
. . . 31 30 29
210
Identification Register
x.....210
Boundary Scan Register*
Selection Circuitry
TDO
TCK _{TAP CONTROLLER}
TMS
24
Integrated Silicon Solution, Inc. — www.issi.com
Rev. 00C
02/20/2013