M4A3-256/128-10YC Lattice, M4A3-256/128-10YC Datasheet - Page 5

• Manufacturer Part Number: M4A3-256/128-10YC
• Manufacturer: Lattice

FUNCTIONAL DESCRIPTION
The fundamental architecture of ispMACH 4A devices (Figure 1) consists of multiple, optimized PAL
blocks interconnected by a central switch matrix. The central switch matrix allows communication between
PAL blocks and routes inputs to the PAL blocks. Together, the PAL blocks and central switch matrix allow
the logic designer to create large designs in a single device instead of having to use multiple devices.
The key to being able to make effective use of these devices lies in the interconnect schemes. In the
ispMACH 4A architecture, the macrocells are flexibly coupled to the product terms through the logic
allocator, and the I/O pins are flexibly coupled to the macrocells due to the output switch matrix. In
addition, more input routing options are provided by the input switch matrix. These resources provide the
flexibility needed to fit designs efficiently.
Notes:
1. 16 for ispMACH 4A devices with 1:1 macrocell-I/O cell ratio (see next page).
2. Block clocks do not go to I/O cells in M4A(3,5)-32/32.
3. M4A(3,5)-192, M4A(3,5)-256, M4A3-384, and M4A3-512 have dedicated clock pins which cannot be used as inputs and do not connect to the central switch
matrix.
Clock/Input
Dedicated
Note 3
Input Pins
Pins
Figure 1. ispMACH 4A Block Diagram and PAL Block Structure
33/
34/
36
Generator
Switch
Matrix
Clock
Logic
Array
Input
with XOR
Allocator
ispMACH 4A Family
Logic
16
4
16
PAL Block
PAL Block
Macrocells
Output/
Buried
16
Note 2
Note 1
16
8
PAL Block
17466G-001
Pins
Pins
Pins
I/O
I/O
I/O
®
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