
Chapter 12. Test
12-33
Test Controller
Note the following:
The 000 mode would be chosen for standard functional operation. None of the test
signals are asserted and all test inputs default to the quiescent 0-driven state.
The CF4e does not contain a PLL, but it is set up such that when mode 010 is chosen
the core goes into an idle mode after reset.
During burn-in scan more, both internal and wrapper scan chains are used. The
memory arrays are active for activities in which randomly applied scan vectors will
be written into and exercise the arrays.
During production scan mode, both internal and wrapper scan chains are used.
Memories external to the core should be write inhibited. This memory lock is to
reduce noise, power, and to create a safe environment for the memory arrays since
scan will randomly toggle the data, address, read-write, and output enable control
signals.
The two BIST encodings put the core into idle mode as well.
Safe mode puts the core into reset, but still allows use of the wrapper scan chains for
testing the peripheral logic. This helps with power issues and to keep the core safe
while other portions of the device are being tested.
6
110
Engineering BIST (EBIST)
7
111
Safe mode
Table 12-6. CF4e Motorola Test Mode Encodings (Continued)
Hex
MTMOD[2:0]
Mode or Action
F
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
n
.