GAL20V8 Lattice Semiconductor, GAL20V8 Datasheet - Page 4

• Manufacturer Part Number: GAL20V8
• Description: High Performance E2CMOS PLD Generic Array Logic
• Manufacturer: Lattice Semiconductor

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.
Note: The development software configures all of the architecture control bits and checks for proper pin usage automatically.
Registered Mode
OE
CLK
XOR
XOR
D
Q
Q
4
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.
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.
Registered Configuration for Registered Mode
Combinatorial 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 controls common CLK for the registered outputs.
- Pin 13 controls common OE for the registered outputs.
- Pin 1 & Pin 13 are permanently configured as CLK &
- SYN=0.
- AC0=1.
- XOR=0 defines Active Low Output.
- XOR=1 defines Active High Output.
- AC1=1 defines this output configuration.
- Pin 1 & Pin 13 are permanently configured as CLK &
OE for registered output configuration.
OE for registered output configuration..
Specifications GAL20V8