13

0453H–PLD–7/05

ATF16V8CZ

8.2

ATF16V8CZ Complex Mode

PAL Device Emulation/PAL Replacement. In the complex mode, combinatorial output and I/O

functions 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

macrocell 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:

16L8

16H8

16P8

Figure 8-4.

Complex Mode Option

9.

ATF16V8CZ 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 permanently configured as combinato-

rial outputs. Other macrocells 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 combinatorial without OE control. The fol-

lowing simple PALs can be emulated using this mode:

10L8 10H8 10P8

12L6 12H6 12P6

14L4 14H4 14P4

16L2 16H2 16P2