Specifications GAL20V8Z

GAL20V8ZD

4

Combinatorial Configuration for Registered Mode

- SYN=0.

- AC0=1.

- XOR=0 defines Active Low Output.

- XOR=1 defines Active High Output.

- AC1=1 defines this output configuration.

- Pin 1(2) & Pin 13(16) are permanently configured as

CLK &

OE for registered output configuration.

Registered Configuration for Registered Mode

- SYN=0.

- AC0=1.

- XOR=0 defines Active Low Output.

- XOR=1 defines Active High Output.

- AC1=0 defines this output configuration.

- Pin 1(2) controls common CLK for the registered

outputs.

- Pin 13(16) controls common

OE for the registered

outputs.

- Pin 1(2) & Pin 13(16) are permanently configured as

CLK &

OE for registered output configuration.

In the Registered mode, macrocells are configured as dedicated

registered outputs or as I/O functions.

Architecture configurations available in this mode are similar to the

common 20R8 and 20RP4 devices with various permutations of

polarity, I/O and register placement.

All registered macrocells share common clock and output enable

control pins. Any macrocell can be configured as registered or I/

O. Up to eight registers or up to eight I/Os are possible in this mode.

Dedicated input or output functions can be implemented as sub-

sets of the I/O function.

Registered outputs have eight product terms per output. I/Os have

seven product terms per output.

Pin 4(5) is used as dedicated power-down pin on GAL20V8ZD. It

cannot be used as functional input.

The JEDEC fuse numbers, including the User Electronic Signature

(UES) fuses and the Product Term Disable (PTD) fuses, are shown

on the logic diagram on the following page.

Note: The development software configures all of the architecture control bits and checks for proper pin usage automatically.

DQ

Q

CLK

OE

XOR

XOR

Registered Mode