ATF20V8BQL datasheet(9/17 Pages) ATMEL

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ATF20V8B

ATF20V8B Complex Mode

PAL Device Emulation/PAL Replacement

In the Complex Mode, combinatorial output and I/O func-

tions are possible. Pins 1 and 11 are regular inputs to the

array. Pins 13 through 18 have pin feedback paths back to

the AND-array, which makes full I/O capability possible.

Pins 12 and 19 (outermost macrocells) are outputs only.

They do not have input capability. In this mode, each mac-

rocell has seven product terms going to the sum term and

one product term enabling the output.

Combinatorial applications with an OE requirement will

make the compiler select this mode. The following devices

can be emulated using this mode:

20L8

20H8

20P8

Complex Mode Operation

ATF20V8B Simple Mode

PAL Device Emulation / PAL Replacement

In the Simple Mode, 8 product terms are allocated to the

sum term. Pins 15 and 16 (center macrocells) are perma-

nently configured as combinatorial outputs. Other macro-

cells can be either inputs or combinatorial outputs with pin

feedback to the AND-array. Pins 1 and 11 are regular

inputs.

The compiler selects this mode when all outputs are combi-

natorial without OE control. The following simple PALs can

be emulated using this mode:

14L8

14H8 14P8

16L6

18H6

16P6

18L4

18H4

18P4

20L2

20H2

20P2

Simple Mode Option

ATF20V8BQL Datasheet(PDF) 9 Page - ATMEL Corporation