LC51024MV-52F484C Lattice, LC51024MV-52F484C Datasheet - Page 7

• Manufacturer Part Number: LC51024MV-52F484C
• Manufacturer: Lattice

Lattice Semiconductor
Figure 6. Dual-OR PT Sharing Array
Product Term Sharing Array
The Product Term Sharing Array (PTSA) consists of 32 inputs from the Dual-OR Array (Expandable PTSA OR) and
32 outputs directly to the macrocells. Each output is the OR term of any combination of the seven Expandable
PTSA OR terms connected to that output. Every Nth macrocell is connected to N-3, N-2, N-1, N, N+1, N+2 and
N+3 PTSA OR terms via a programmable connection. This wraps around the logic, for example, Macrocell 0 gets
its logic from 29, 30, 31, 0, 1, 2, 3. The Expandable PTSA OR used in conjunction with the PTSA allows wide func-
tions to be implemented easily and efficiently. Without using the Expandable PTSA OR capability, the greatest
number of product terms that can be included in a single function with one pass of delay is 35. Up to 160 product
terms can be included in a single function through the use of the expandable PTSA OR capability. Figure 7 shows
the graphical representation of the PTSA.
Figure 7. Product Term Sharing Array (PTSA)
From PT0
From PT1
From PT2
From PT3
From PT4
PTSA OR 29
PTSA OR 30
PTSA OR 31
PTSA OR 0
PTSA OR 1
PTSA OR 2
PTSA OR 3
N
From
n+7
7
n-7
To
Carry
In
Carry
Out
ispXPLD 5000MX Family Data Sheet
PTSA Bypass
PT Preset
Macrocell 0
Macrocell 1
Macrocell 2
Macrocell 29
Macrocell 30
Macrocell 31
PT Reset
PT Clock
PT OE
To I/O Block
To Macrocell
To PTSA
To Macrocell
To Macrocell
To Macrocell