FEEDBACK AND OUTPUT CONFIGURATION

TIBPAL22V10-20M

HIGH-PERFORMANCE IMPACT-X

™ PROGRAMMABLE ARRAY LOGIC CIRCUITS

SRPS012A – D3523, JUNE 1990 – REVISED MARCH 1992

POST OFFICE BOX 655303

7

C1

1S

1D

R

S1 = 0

S0 = 0

C1

1S

1D

R

S1 = 0

S0 = 1

REGISTER FEEDBACK, REGISTERED, ACTIVE-LOW OUTPUT

REGISTER FEEDBACK, REGISTERED, ACTIVE-HIGH OUTPUT

S1 = 1

S0 = 0

S1 = 1

S0 = 1

I/O FEEDBACK, COMBINATIONAL, ACTIVE-LOW OUTPUT

I/O FEEDBACK, COMBINATIONAL, ACTIVE-HIGH OUTPUT

MACROCELL FEEDBACK AND OUTPUT FUNCTION TABLE

FUSE SELECT

S1

S0

0

0

Register feedback

Registered

Active low

0

1

Register feedback

Registered

Active high

1

0

I/O feedback

Combinational

Active low

1

1

I/O feedback

Combinational

Active high

0 = unblown fuse, 1 = blown fuse

S1 and S0 are select-function fuses as shown in the output logic macrocell

diagram.

Figure 1. Resultant Macrocell Feedback and Output Logic After Programming