1. Sequential Programmable Devices

2. Sequential Programmable Devices
The combinational PLD consist only gates
Sequential Programmable Devices includes both gates and filp-flop
Type of sequential Programmable Devices:
Sequential (simple) programmable logic device (SPLD)
Complex programmable logic device (CPLD)
Field programmable gate array (FPGA)

3. SPLD SPLD: consist PAL and D flip-flop
Each section in SPLD is called Microcell

4. SPLD The basic microcell logic A typical SPLD has from 8 to 10
AND-OR array
Edge-triggered D flip-flop
Three-state buffer(inverter)
A typical SPLD
has from 8 to 10
macrocells within
one IC package

5. CPLD
CPLD is a collection of individual PLDs on a single integrated circuit
Each PLD typically contains from 8 to 16 macroceIls
CPLD has two levels of programmability:
Each PLD block
Interconnections between the PLDs
Each I/0 pin is driven by
a three state buffer and
can be programmed to act
as input or output

6. FPGA
FPGA is a VLSI circuit that can be programmed at the user's location
Consist of:
hundreds or thousands
of logic blocks
Programmable interconnection
programmable input and
output blocks

7. Logic block Used to implement any boolean function Consist of:
Look up table (LUTs) , Multiplexers , PLD blocks or NAND gates (implemented logic function)
Multiplexers (select 1 of N inputs)
Flip-flop, Registers. Clocked Storage
elements.

8. Interconnection (Routing)
FPGAs have 3 programmable routing resources :
Vertical and horizontal routing channels
Connection boxes
connect input and output pins of the CLBs to wires of the vertical or the horizontal routing channels
Switch boxes
connect wire segments in the horizontal and vertical channels
Technology of connection
Static RAM
Anti fuse
EPROM
EEPROM

9. I/O blocks
They allow the pins of the FPGA chip to function either as input pins, output pins or input/output pins
Programmable I/O

10. Circuit compilation

11. Major FPGA Vendors SRAM-based FPGAs Flash & antifuse FPGAs
Xilinx, Inc.
Altera Corp.
Atmel
Lattice Semiconductor
Flash & antifuse FPGAs
Actel Corp.
Quick Logic Corp.

12. Altera DE2-70