ASICs...THE COURSE (1 WEEK)
1
PROGRAMMABLE
ASICs
4.1 The Antifuse
Key concepts: programmable logic devices (PLDs) ? field-programmable gate arrays
(FPGAs) ? programming technology ? basic logic cells ? I/O logic cells ? programmable inter-
connect ? software to design and program the FPGA
Actel antifuse
antifuse ? programming current (about 5mA) ? (PLICE‘) ? oxide–nitride–oxide (ONO) dielec-
tric ? Activator ? in-system programming (ISP) ? gang programmers ? one-time programma-
ble (OTP) FPGAs
n+ antifusediffusion
antifusepolysilicon
2 λ<10nm
oxide–nitride–oxide(ONO) dielectric20nm
antifuselinkantifuse polysilicon
n+ antifuse diffusion
ONO dielectric
2 λ
n+ antifusediffusion antifusepolysilicon
(a) (b) (c)
antifuse
contacts2 λ
4
2 SECTION 4 PROGRAMMABLE ASICs ASICS... THE COURSE
Number of
antifuses on Actel FPGAs
Device Antifuses
A1010 112,000
A1020 186,000
A1225 250,000
A1240 400,000
A1280 750,000
The resistance of blown Actel antifuses
antifuse resistance/ ?
0
100percentage
ASICs... THE COURSE 4.1 The Antifuse 3
4.1.1 Metal–Metal Antifuse
Metal–metal antifuse
QuickLogic metal–metal antifuse (ViaLink‘) ? alloy of tungsten, titanium, and silicon ? bulk re-
sistance of about 500m?cm
Resistance values for the QuickLogic
metal–metal antifuse
m1
m2
SiO2
SiO2 via
link link
m2amorphous Si
(a) (b)
SiO2 tungstenplug
m3 4 λ 4 λ
amorphous Si 2 λ m3
m2
2 λ2 λ
antifuse resistance/ ?
0
100percentage
4 SECTION 4 PROGRAMMABLE ASICs ASICS... THE COURSE
4.2 Static RAM
4.3 EPROM and EEPROM Technology
Xilinx SRAM (static RAM) configura-
tion cell
? use in reconfigurable hardware
? use of programmable read-only
memory or PROM to hold configu-
ration
An EPROM transistor
(a) With a high (>12V) programming voltage, VPP, applied to the drain, electrons gain
enough energy to “jump” onto the floating gate (gate1)
(b) Electrons stuck on gate1 raise the threshold voltage so that the transistor is always off
for normal operating voltages
(c) UV light provides enough energy for the electrons stuck on gate1 to “jump” back to the
bulk, allowing the transistor to operate normally
Facts and keywords: Altera MAX 5000 EPLDs and Xilinx EPLDs both use UV-erasable
electrically programmable read-only memory (EPROM) ? hot-electron injection or avalanche
injection ? floating-gate avalanche MOS (FAMOS)
DATA
READ orWRITE
QQ' configurationcontrol
source drain+VPPGND
electronsGND
+VGS > Vtn
gate1gate2 source drain+VDSGND
no channel bulkGND
+VGS > Vtn hν
UV light
(a) (b) (c)
bulkbulk
ASICs... THE COURSE 4.4 Practical Issues 5
4.4 Practical Issues
4.4.1 FPGAs in Use
? inventory
? risk inventory or safety supply
? just-in-time (JIT)
? printed-circuit boards (PCBs)
? pin locking or I/O locking
4.5 Specifications
? qualification kit
? down-binning
4.6 PREP Benchmarks
? Programmable Electronics Performance Company (PREP)
? http://www.prep.org
Hardware security key
computer-aided engineering (CAE) tools ? PC vs. workstation ?
ease of use ? cost of ownership
6 SECTION 4 PROGRAMMABLE ASICs ASICS... THE COURSE
4.7 FPGA Economics
Xilinx part-naming convention
Not all parts are available in all packag-
es
Some parts are packaged with fewer
leads than I/Os
Programmable ASIC part codes
Item Code Description Code Description
Manufac-
turer’s
code
A Actel ATT AT&T (Lucent)
XC Xilinx isp Lattice Logic
EPM Altera MAX M5 AMD MACH 5 is on the
device
EPF Altera FLEX QL QuickLogic
CY7C Cypress
Package
type
PL or
PC
plastic J-leaded chip carrier,
PLCC
VQ very thin quad flatpack,
VQFP
PQ plastic quad flatpack, PQFP TQ thin plastic flatpack, TQFP
CQ or
CB
ceramic quad flatpack, CQFP PP plastic pin-grid array, PPGA
PG ceramic pin-grid array, PGA WB,
PB
ball-grid array, BGA
Application C commercial B MIL-STD-883
I industrial E extended
M military
XC4010-10 PG156C
device typespeedpackage
number of pinstemperature range
ASICs... THE COURSE 4.7 FPGA Economics 7
1992 base Actel
FPGA prices
1992 base Xilinx XC3000
FPGA prices
Actel part 1H92 base price Xilinx part 1H92 base price
A1010A-PL44C $23.25 XC3020-50PC68C $26.00
A1020A-PL44C $43.30 XC3030-50PC44C $34.20
A1225-PQ100C $105.00 XC3042-50PC84C $52.00
A1240-PQ144C $175.00 XC3064-50PC84C $87.00
A1280-PQ160C $305.00 XC3090-50PC84C $133.30
8 SECTION 4 PROGRAMMABLE ASICs ASICS... THE COURSE
4.7.1 FPGA Pricing
“How much do FPGAs cost?” ? “How much does a car cost?” ? pricing matrix
Actel price adjustment factors
Purchase quantity, all types
(1–9) (10–99) (100–999)
100% 96% 84%
Purchase time, in (100–999) quantity
1H92 2H92 93
100% 80–95% 60–80%
Qualification type, same package
Commercial Industrial Military 883-B
100% 120% 150% 230–300%
Speed bin1
ACT 1-Std ACT 1-1 ACT 1-2 ACT 2-Std ACT 2-1
100% 115% 140% 100% 120%
Package type
A1010: PL44, 64, 84 PQ100 PG84
100% 125% 400%
A1020: PL44, 64, 84 PQ100 JQ44, 68, 84 PG84 CQ84
100% 125% 270% 275% 400%
A1225: PQ100 PG100
100% 175%
A1240: PQ144 PG132
100% 140%
A1280: PQ160 PG176 CQ172
100% 145% 160%
1Actel bins: Std=standard speed grade; 1=medium speed grade; 2=fastest speed grade
ASICs... THE COURSE 4.7 FPGA Economics 9
4.7.2 Pricing Examples
base prices and adjustment factors ? “sticker price”
? Marshall at http://marshall.com, carry Xilinx
? Hamilton-Avnet, at http://www.hh.avnet.com, carry Xilinx
? Wyle, at http://www.wyle.com carries Actel and Altera
Example Actel part-price calculation
Example: A1020A-2-PQ100 in (100–999) quantity, purchased 1H92.
Factor Example Value
Base price A1020A $43.30
Quantity 100–999 84%
Time 1H92 100%
Qualification type Industrial (I) 120%
Speed bin1 2 140%
Package PQ100 125%
Estimated price (1H92) $76.38
Actual Actel price (1H92) $75.60
1The speed bin is a manufacturer’s code (usually a number) that follows the family part number
and indicates the maximum operating speed of the device
10 SECTION 4 PROGRAMMABLE ASICs ASICS... THE COURSE
4.8 Summary
All FPGAs have the following key elements:
? The programming technology
? The basic logic cells
? The I/O logic cells
? Programmable interconnect
? Software to design and program the FPGA
Programmable ASIC technologies
Actel Xilinx LCA1 Altera EPLD Xilinx EPLD
Programming
technology
Poly–diffusion
antifuse, PLICE
Erasable SRAM
ISP
UV-erasable
EPROM (MAX 5k)
EEPROM (MAX
7/9k)
UV-erasable
EPROM
Size of
programming
element
Small but requires
contacts to metal
Two inverters plus
pass and switch
devices. Largest.
One n-channel
EPROM device.
Medium.
One n-channel
EPROM device.
Medium.
Process Special: CMOS
plus three extra
masks.
Standard CMOS Standard EPROM
and EEPROM
Standard EPROM
Program-
ming method
Special hardware PC card, PROM,
or serial port
ISP (MAX 9k) or
EPROM program-
mer
EPROM program-
mer
QuickLogic Crosspoint Atmel Altera FLEX
Programming
technology
Metal–metal
antifuse, ViaLink
Metal–polysilicon
antifuse
Erasable SRAM.
ISP.
Erasable SRAM.
ISP.
Size of
programming
element
Smallest Small Two inverters plus
pass and switch
devices. Largest.
Two inverters plus
pass and switch
devices. Largest.
Process Special, CMOS
plus ViaLink
Special, CMOS
plus antifuse
Standard CMOS Standard CMOS
Program-
ming method
Special hardware Special hardware PC card, PROM,
or serial port
PC card, PROM,
or serial port
1Lucent (formerly AT&T) FPGAs have almost identical properties to the Xilinx LCA family
ASICs... THE COURSE 4.9 Problems 11
4.9 Problems
12 SECTION 4 PROGRAMMABLE ASICs ASICS... THE COURSE
