Integrated circuit scan-in/scan-out method

Abstract

Abstract PURPOSE:To improve the reliability and diagnostic performance by providing a scan register to an integrated circuit and storing a scan command address to the register so as to reduce number of pins of the integrated circuit applying scan-in/scan-out. CONSTITUTION:A terminal connected to scan-in interface signal lines 1-5 is provided to the integrated circuit for scan-in/scan-out system and a scan-in data SID from the signal line 1 is fed to a scan register 6. Further, a scan enable SE and a scan timing SIT2 from the signal lines 3, 4 are fed to a scan bit counter 7 and the enable SE is fed to a scan decoder 12. The scan address and control information inputted serially to the said circuit are set to the register 6 by the counter 7. Then a scan object FF15 uses a command of the register 6 so as to discriminate scan-in or scan-out, allowing to execute the scan-in or scan-out with less number of pins.

Inventors

• 👤 Kiyoshi Yada
• 👤 矢田　潔
• 👤 Masao Kato
• 👤 正男 加藤

Bibliographic Details