CY7C1360C
CY7C1362C
Document #: 38-05540 Rev. *H Page 11 of 31
IEEE 1149.1 Serial Boundary Scan (JTAG)The CY7C1360C/CY7C1362C incorporates a serial boundary
scan test access port (TAP) in the BGA package only. The
TQFP package does not offer this functionality. This part
operates in accordance with IEEE Standard 1149.1-1900, but
doesn’t have the set of functions required for full 1149.1
compliance. These functions from the IEEE specification are
excluded because their inclusion places an added delay in the
critical speed path of the SRAM. Note the TAP controller
functions in a manner that does not conflict with the operation
of other devices using 1149.1 fully compliant TAPs. The TAP
operates using JEDEC-standard 3.3V or 2.5V I/O logic levels.
The CY7C1360C/CY7C1362C contains a TAP controller,
instruction register, boundary scan register, bypass register,
and ID register.
Disabling the JTAG Feature
It is possible to operate the SRAM 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 inter-
nally pulled up and may be unconnected. They may alternately
be connected to VDD through a pull-up resistor. TDO should be
left unconnected. Upon power-up, the device will come up in
a reset state which will not interfere with the operation of the
device.TAP Controller State Diagram
The 0/1 next to each state represents the value of TMS at the
rising edge of TCK.
Test Access Port (TAP)
Test Clock (TCK)
The test clock is used only with the 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 used to give commands to the TAP controller
and is sampled on the rising edge of TCK. It is allowable to
leave this ball unconnected if the TAP is not used. The ball is
pulled up internally, resulting in a logic HIGH level.
Test Data-In (TDI)
The TDI ball is used to serially input information into the
registers and 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, see TAP
Controller State Diagram. TDI is internally pulled up and can
be unconnected if the TAP is unused in an application. TDI is
connected to the most significant bit (MSB) of any register.
(See Tap Controller Block Diagram.)
Test Data-Out (TDO)
The TDO output ball is used to serially clock data-out from the
registers. The output is active depending upon the current
state of the TAP state machine. The output changes on the
falling edge of TCK. TDO is connected to the least significant
bit (LSB) of any register. (See Tap Controller State Diagram.)
Truth Table for Read/Write[5, 9]
Function (CY7C1362C) GW BWE BWBBWA
Read H H X X
Read H L H H
Write Byte A – (DQA and DQPA)HLHL
Write Byte B – (DQB and DQPB)HLLH
Write Bytes B, A H L L L
Write All Bytes H L L L
Write All Bytes L X X X
TEST-LOGIC
RESET
RUN-TEST/
IDLE SELECT
DR-SCAN SELECT
IR-SCAN
CAPTURE-DR
SHIFT-DR
CAPTURE-IR
SHIFT-IR
EXIT1-DR
PAUSE-DR
EXIT1-IR
PAUSE-IR
EXIT2-DR
UPDATE-DR
EXIT2-IR
UPDATE-IR
1
1
1
0
1 1
0 0
1 1
1
0
0
0
0 0
0
0
0 0
1
0
1
1
0
1
0
1
1
1
1 0
[+] Feedback