TIBPAL20L8-25C Datasheet, PDF (11/17 Pages) Texas Instruments – LOW-POWER HIGH-PERFORMANCE IMPACT E PAL CIRCUITS

TIBPAL20L8-25C, TIBPAL20R4-25C, TIBPAL20R6-25C, TIBPAL20R8-25C
LOW-POWER HIGH-PERFORMANCE IMPACT ™ PAL^® CIRCUITS
SRPS022 – D2920, MAY 1987 – REVISED MARCH 1992
programming information
Texas Instruments programmable logic devices can be programmed using widely available software and
inexpensive device programmers.
Complete programming specifications, algorithms, and the latest information on hardware, software, and
firmware are available upon request. Information on programmers capable of programming Texas Instruments
programmable logic is also available, upon request, from the nearest TI field sales office, local authorized TI
distributor, or by calling Texas Instruments at [phone].
preload procedure for registered outputs (see Figure 1 and Notes 2 and 3)
The output registers can be preloaded to any desired state during device testing. This permits any state to be
tested without having to step through the entire state-machine sequence. Each register is preloaded individually
by following the steps given below.
Step 1.
Step 2.
Step 3.
Step 4.
With V_CC at 5 volts and Pin 1 at V_IL, raise Pin 13 to V_IHH.
Apply either V_IL or V_IH to the output corresponding to the register to be preloaded.
Pulse Pin 1, clocking in preload data.
Remove output voltage, then lower Pin 13 to V_IL. Preload can be verified by observing the
voltage level at the output pin.
Pin 13
Pin 1
tsu
td
td
tw
VIHH
VIL
VIH
VIL
Registered I/O
Input
VIH
VOH
Output
VIL
VOL
Figure 1. Preload Waveforms
NOTES: 2. Pin numbers shown are for JT and NT packages only. If chip carrier socket adapter is not used, pin numbers must be changed
accordingly.
3. td = tsu = th = 100 ns to 1000 ns VIHH = 10.25 V to 10.75 v
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