TheTTL - Al Kossow's Bitsavers

TIBPAL20L 10, TIBPAL20X4, TIBPAL20X8, TIBPAL20X10
HIGH·PERFORMANCE EXCLUSIVE·OR IMPACr M PAL CIRCUITS
preload procedures
preload procedure for registered outputs
Step 1
Step 2
Step 3
Step 4
Step 5
With Vee at 5 volts, raise Pin 13 (OE) to VIHH to disable the outputs and clear the
registers (output goes low). Since the outputs are low, only high levels need be preloaded.
Raise the selected output to be preloaded high to VIHH.
Lower Pin 13 to VIH.
Remove the voltages applied to the outputs. (At least a 1 OO-nswait is required between step 3
and step 4)
Lower Pin 13 to VIL to verify preload.
."
(D'
c::
-lJ .....
o
(Q
.....
D,)
3
3
D,)
C"'
CD
r- .
o
(Q
c;-
(PRELOAD PIN 13)
SELECTED
OUTPUT
TO PRELOAD
V
security fuse programming
1------"'------------ -- VIHH
I
100 ns I I 100 ns
MIN MIN I
~ j4---+I ~ I I VIL
I I I I ~
i I--------l~ -!~i~----:~~
Q )()()()()()()OO . ~ VOl
PIN 10
I
---~.
PRELOAD WAVEFORMS
\-----'2.5V
t w3----+.·
SECURITY FUSE PROGRAMMING WAVEFORMS
OV
VERIFY
NOTE: Pin numbers shown apply only for the DIP package. If a chip carrier socket adaptor is not used, pin numbers must be changed
accordingly.
3-88 TEXAS.
INSTRUMENTS
POST OFFICE BOX 225012 • DALLAS. TEXAS 75265.