512Kx36 & 1Mx18 Pipelined N
t
RAM
TM
- 15 -
Rev 3.0
Nov. 2003
K7N161801A
K7N163601A
IEEE 1149.1 TEST ACCESS PORT AND BOUNDARY SCAN-JTAG
This part contains an IEEE standard 1149.1 Compatible Test Access Port(TAP). The package pads are monitored by the Serial Scan
circuitry when in test mode. This is to support connectivity testing during manufacturing and system diagnostics. Internal data is not
driven out of the SRAM under JTAG control. In conformance with IEEE 1149.1, the SRAM contains a TAP controller, Instruction Reg-
ister, Bypass Register and ID register. The TAP controller has a standard 16-state machine that resets internally upon power-up,
therefore, TRST signal is not required. It is possible to use this device without utilizing the TAP. To disable the TAP controller without
interfacing with normal operation of the SRAM, TCK must be tied to V
SS
to preclude mid level input. TMS and TDI are designed so an
undriven input will produce a response identical to the application of a logic 1, and may be left unconnected. But they may also be
tied to V
DD
through a resistor. TDO should be left unconnected.
TAP Controller State Diagram
JTAG Block Diagram
SRAM
CORE
BYPASS Reg.
Identification Reg.
Instruction Reg.
Control Signals
TAP Controller
TDO
TDI
TMS
TCK
Test Logic Reset
Run Test Idle
0
1
1
1
1
0
0
0
1
0
1
1
0
0
0
1
0
1
1
1
0
0
0
0
0
0
0
Select DR
Capture DR
Shift DR
Exit1 DR
Pause DR
Exit2 DR
Update DR
Select IR
Capture IR
Shift IR
Exit1 IR
Pause IR
Exit2 IR
Update IR
1
1
1
1
1
JTAG Instruction Coding
NOTE
:
1. Places DQs in Hi-Z in order to sample all input data regardless of other
SRAM inputs. This instruction is not IEEE 1149.1 compliant.
2. Places DQs in Hi-Z in order to sample all input data regardless of other
SRAM inputs.
3. TDI is sampled as an input to the first ID register to allow for the serial shift
of the external TDI data.
4. Bypass register is initiated to V
SS
when BYPASS instruction is invoked. The
Bypass Register also holds serially loaded TDI when exiting the Shift DR
states.
5. SAMPLE instruction dose not places DQs in Hi-Z.
6. This instruction is reserved for future use.
IR2
IR1
IR0
Instruction
TDO Output
Notes
0
0
0
EXTEST
Boundary Scan Register
1
0
0
1
IDCODE
Identification Register
3
0
1
0
SAMPLE-Z
Boundary Scan Register
2
0
1
1
BYPASS
Bypass Register
4
1
0
0
SAMPLE
Boundary Scan Register
5
1
0
1
RESERVED
Do Not Use
6
1
1
0
BYPASS
Bypass Register
4
1
1
1
BYPASS
Bypass Register
4