Specifications GAL16V8
REGISTERED MODE
In the Registered mode, macrocells are configured as dedicated
registered outputs or as I/O functions.
mode. Dedicated input or output functions can be implemented
as subsets of the I/O function.
Architecture configurations available in this mode are similar to
the common 16R8 and 16RP4 devices with various permutations
of polarity, I/O and register placement.
Registered outputs have eight product terms per output. I/O's
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.
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/O's are possible in this
CLK
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 controls common CLK for the registered outputs.
- Pin 11 controls common OE for the registered outputs.
- Pin 1 & Pin 11 are permanently configured as CLK &
OE.
D
Q
Q
XOR
OE
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 & Pin 11 are permanently configured as CLK &
OE.
XOR
Note: The development software configures all of the architecture control bits and checks for proper pin usage automatically.
1996 Data Book
3-68
LATTICE [ LATTICE SEMICONDUCTOR ]
