The 'BCT8373A scan test devices with octal D-type latches are
members of the Texas Instruments SCOPETM testability
circuit family. This family of devices supports IEEE Standard
1149.1-1990 boundary scan to facilitate testing of complex circuit
board assemblies. Scan access to the test circuitry is accomplished
via the 4-wire test access port (TAP) interface.
In the normal mode, these devices are functionally equivalent to
the 'F373 and 'BCT373 octal D-type latches. The test circuitry can be
activated by the TAP to take snapshot samples of the data appearing
at the device terminals or to perform a self test on the boundary
test cells. Activating the TAP in normal mode does not affect the
functional operation of the SCOPETM octal latches.
In the test mode, the normal operation of the SCOPETM
octal latches is inhibited and the test circuitry is enabled to
observe and control the I/O boundary of the device. When enabled, the
test circuitry can perform boundary scan test operations, as
described in IEEE Standard 1149.1-1990.
Four dedicated test terminals are used to control the operation of
the test circuitry: test data input (TDI), test data output (TDO),
test mode select (TMS), and test clock (TCK). Additionally, the test
circuitry can perform other testing functions such as parallel
signature analysis (PSA) on data inputs and pseudo-random pattern
generation (PRPG) from data outputs. All testing and scan operations
are synchronized to the TAP interface.
The SN54BCT8373A is characterized for operation over the full
military temperature range of -55°C to 125°C. The
SN74BCT8373A is characterized for operation from 0°C to