SN74BCT8245A IEEE Std 1149.1 (JTAG) Boundary-Scan Test Device With Octal Bus Transceivers |

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IEEE Std 1149.1 (JTAG) Boundary-Scan Test Device With Octal Bus Transceivers

IEEE Std 1149.1 (JTAG) Boundary-Scan Test Device With Octal Bus Transceivers - SN74BCT8245A


The 'BCT8245A scan test devices with octal bus transceivers are members of the Texas Instruments SCOPETM 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 functionally equivalent to the 'F245 and 'BCT245 octal bus transceivers. 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 bus transceivers.

In the test mode, the normal operation of the SCOPETM octal 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 as described in IEEE Standard 1149.1-1990.


Four dedicated test terminals 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 performs 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 SN54BCT8245A is characterized for operation over the full military temperature range of -55°C to 125°C. The SN74BCT8245A is characterized for operation from 0°C to 70°C.


  • Members of the Texas Instruments SCOPETM Family of Testability Products
  • Octal Test-Integrated Circuits
  • Functionally Equivalent to 'F245 and 'BCT245 in the Normal- Function Mode
  • Compatible With the IEEE Standard 1149.1-1990 (JTAG) Test Access Port and Boundary-Scan Architecture
  • Test Operation Synchronous to Test Access Port (TAP)
  • Implement Optional Test Reset Signal by Recognizing a Double-High-Level Voltage (10 V) on TMS Pin
  • SCOPETM Instruction Set
    • IEEE Standard 1149.1-1990 Required Instructions, Optional INTEST, CLAMP, and HIGHZ
    • Parallel-Signature Analysis at Inputs
    • Pseudo-Random Pattern Generation From Outputs
    • Sample Inputs/Toggle Outputs
  • Package Options Include Plastic Small-Outline (DW) Packages, Ceramic Chip Carriers (FK), and Standard Plastic and Ceramic 300-mil DIPs (JT, NT)


SCOPE is a trademark of Texas Instruments Incorporated.


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Part number Order Technology Family VCC (Min) (V) VCC (Max) (V) Bits (#) Voltage (Nom) (V) F @ nom voltage (Max) (MHz) ICC @ nom voltage (Max) (mA) tpd @ nom Voltage (Max) (ns) IOL (Max) (mA) IOH (Max) (mA) Operating temperature range (C) Package Group
SN74BCT8245A Order now BCT     4.5     5.5     8     5     70     52     10     64     -15     0 to 70     SOIC | 24    
SN54BCT8245A Samples not available BCT     4.5     5.5     8     5     70     52     10     64     -15     -55 to 125     CDIP | 24
LCCC | 28