TheTTL - Al Kossow's Bitsavers

programming procedure for array fuses (see Note 4)
TIB82S1058
16 x 48 x 8FIElD·PROGRAMMABlE lOGIC SEOUENCER
WITH 3·STATE OUTPUTS OR PRESET
Array fuses are programmed using a binary select method. Each fuse can be addressed by selecting the
appropriate input line or sum of products line (row address) and product line (column address). The addresses
for selecting input lines, sum of products lines, and product lines are shown in Tables 1 and 2.
SETUP
Step 1: Set PGM ENABLE to GND.
Step 2: Apply address to inputs.
Step 3: Set PGM to VIH.
Step 4: Set PIV to VIL.
Step 5: Wait td, set VCC to VCC1.
PROGRAM
Step 1: Wait td, raise PIV to VIH.
Step 2: Wait td, raise PGM ENABLE to VIHH.
Step 3: Wait td, pulse PGM to VIL for tw1.
Step 4: Wait td, return PGM ENABLE to GND.
Step 5: Wait td, return PIV to VIL.
VERIFY
Step 1:. Wait td, lower PGM to VIL.
Step 2: After t w 2, read sense: A VIH level indicates a blown fuse.
Step 3: Raise PGM to VIH.
NEXT ADDRESS SELECT
Step 1: After td, lower VCC to GND.
Step 2: For the same product line wait td, then apply new input line or sum-of-products line address.
Step 3: For different product line wait td, apply new input line or sum-of-products line address, then apply
new product line address.
Step 4: Wait td, set VCC at VCC1.
Step 5: Continue with program or verify sequence.
NOTE 4: Input lines and sum of product lines are also referred to as variables. Product lines are also referred to as transition terms.
CJ
'0,
o
...J
Q)
:c
co
E
E
CO
a..
C)
o
a..
c..
-C
Q)
u:
TEXAS ~
INSTRUMENlS
POST OFFICE BOX 225012 • DALLAS. TEXAS 75265
3-129