Members of the Texas Instruments
SCOPE E Family of Testability Products
Members of the Texas Instruments
WidebusE Family
Compatible With the IEEE Standard
1149.1-1990 (JTAG) Test Access Port and
Boundary-Scan Architecture
SCOPE E Instruction Set
– IEEE Standard 1149.1-1990 Required
Instructions and Optional CLAMP and
HIGHZ
– Parallel-Signature Analysis at Inputs
– Pseudo-Random Pattern Generation
From Outputs
– Sample Inputs/Toggle Outputs
– Binary Count From Outputs
– Device Identification
– Even-Parity Opcodes
State-of-the-Art EPIC-IIBE BiCMOS Design
Significantly Reduces Power Dissipation
Packaged in Plastic Shrink Small-Outline
(DL) and Thin Shrink Small-Outline (DGG)
Packages and 380-mil Fine-Pitch Ceramic
Flat (WD) Packages

description
The ’ABT18640 scan test devices with 18-bit
inverting bus transceivers are members of the
Texas Instruments SCOPEE testability
integrated-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 18-bit inverting bus transceivers. They can be used either as two 9-bit
transceivers or one 18-bit transceiver. The test circuitry can be activated by the TAP to take snapshot samples
of the data appearing at the device pins or to perform a self test on the boundary-test cells. Activating the TAP
in the normal mode does not affect the functional operation of the SCOPEE bus transceivers.
Data flow is controlled by the direction-control (DIR) and output-enable (OE) inputs. Data transmission is
allowed from the A bus to the B bus or from the B bus to the A bus, depending on the logic level at DIR. OE can
be used to disable the device so that the buses are effectively isolated.
In the test mode, the normal operation of the SCOPEE bus transceivers 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 according to the protocol described in IEEE Standard 1149.1-1990.