C165UTAH
Addendum
Addendum 2 2001-04-18
2 Boundary Scan / JTAG / Test Interface Signals/OCDS
Page 25
Table 7 Boundary Scan / JTAG / Test Interface Signals/OCDS
Pin No. Symbol Input (I)
Output (O)
Function
6TMS I Boundary Scan Test Mode Select Input,
internal pull-up.
144 TRST I Boundary Scan Test Reset. There is an internal
pull-up device implemented. TRST is low active,
which means the boundary scan tap controller
resets while TRST = ’0’. For normal operation,
•TRST
can be connected to a LOW signal
(using ’0’ signal or external pull-down device)
to keep the tap controller in reset mode, or
•TRST
can be left open. In this case, the reset
is performed using the TMS/TCK signals
according to IEEE 1149.1
In boundary scan test mode, TRST can be left
open, since the internal pull-up device provides
the necessary HIGH signal.