TheTTL - Al Kossow's Bitsavers

TIBPALR19L8, TIBPALR19R4, TIBPALR19R6, TIBPALR19R8
HIGH·PERFORMANCE REGISTERED·INPUT PAL CIRCUITS
programming procedure for array fuses
Array fuses are programmed using a linear select method. Each fuse can be opened by selecting the
appropriate (one of 38) input line and then pulsing the correct (one of 64) product line. The levels for selecting
input lines and product lines are shown in Tables 1 and 2.
Step 1
Step 2
Step 3
Step 4
Step 5
Step 6
Step 7
Raise PGM ENABLE to VIHH.
Select an input line by applying appropriate levels to L/R and PI pins.
Begin selection of the output line with appropriate conditions on PA pins.
Pulse INCLK to VIH.
Raise VCC to VIHH.
Blow the fuse by pulsing the appropriate PO pin to VIHH as shown in Table 2 for the product line.
Return VCC to 5 volts and pulse PGM VERIFY. The PO pin selected in Step 6 wilf be less than
VOL if the fuse is open.
Steps 1 thru 7 may be repeated if the verification does not indicate that the fuse was successfulfy
programmed (blown), but no more than 4 times. Verification is possible only with the verify-protect fuse
intact.
II
programming waveforms for array fuses
To prevent further verification, two last fuses may be blown by raising PGM ENABLE and PGM VERIFY
to 16 ± 0.5 volt. VCC is required to be at 0 during this operation.
.GM ENABLE ): ~----- V"
tsu """'f++f
PI.~;~~;~E~NS~: i
(SEE TABLES I I
VIHH
+t I-th
\r--l------- :::H
1-: r-tw
INCLK ----!-n------------------------------------------ ::~
1 AND 21 -.: :-tsu VIL
Vcc
I
I
___ -+jJ I
: .j: K
-------------------------- VIHH
I"", -------------------- 6 v
----~~u~---t-t~~t_---------------------
OV
I r+-tw1-+j I
(S:'~;:!2( ;xcl-f\---T~ :::"
I td21--'l. @
L -t r+- t w2
tci1~ I VIH
PGMVERIFY
-----------------~ ~------------------------------- VIL
CD A high level during the verify interval indicates that programming has not been successful.
@ A low level during the verify interval indicates that programming has been successful.
n
3-102 TEXAS •
INSTRUMENTS
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