Gérard: The Hard Man
behind the Soft Core
Satnam Singh
Microsoft Research, Cambridge UK
The University of Birmingham
!
multiple
independent
multi-ported
memories
fine-grain
parallelism
and
pipelining
hard and soft
embedded
processors
ELF File
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.bit File
0101110001110001
1101001110011001
0011100011100101
0110001110001110
BlockRam Memory Map (.bmm)
DATA2BRAM
.mem File
0101110001110001
1101001110011001
0011100011100101
0110001110001110
New
.bit File
0101110001110001
1101001110011001
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# CPU address space 0xFFFFE000 - 0xFFFFFFFF.
ADDRESS_BLOCK dramctlr
BUS_BLOCK [0xFFFFF000:0xFFFFFFFF]
xrefdes/dramctlr/bram0 [7:0]
LOC=RAMB16_X0Y0;
xrefdes/dramctlr/bram1 [15:8] LOC=RAMB16_X1Y0;
xrefdes/dramctlr/bram2 [23:16] LOC=RAMB16_X2Y0;
. . .
END_BUS_BLOCK;
END_ADDRESS_BLOCK;
ZBT
SSRAM
SDRAM
DDR
SDRAM
ROM
ZBT SSRAM
Controller
SDRAM
Controller
DDR SDRAM
Controller
External Bus
Controller
OPB
OPB Bridge
On-Chip
Peripheral
CoreConnect Processor Local Bus (PLB) Arbiter
I-Cache PLB
405
PPC
OPB Bridge
D-Cache PLB
High-Speed
Peripheral
CoreConnect OPB
(On-Chip Peripheral Bus)
On-Chip
Peripheral
locks
monitors
condition variables
spin locks
priority inversion
PLDI 1998
PLDI 1999
1
2
3
4
5
PLDI 2000
80
70
60
50
Series1
40
Series2
30
20
10
0
1
2
3
4
5
6
POPL 1998
POPL 1999
POPL 2000
ray of light
Signal
Esterel
Jazz
Lustre
SHIM
PRET-C
San Jose, 6 June 2003
Sylvan Dissoubray
Gérard wearing Satnam’s ring
Satnam wearing Gérard’s ring
San Jose, 6 June 2003
Gérard Berry
Nicolas
Halbwachs
Albert
Benveniste
Synchronous Programming Language Combat Team
Zero delay example: Newtonian Mechanics
Concurrency + Determinism
Calculations are feasible
Predictable delay examples: sound, light, waves
• Wait long enough, same result as 0-delay !
• Zero delay and predictable delay are fully compatible
• Constructive semantics is the unification
• A theory of causality for reactive systems
• Clocked digital circuits paradigm
Safe State Machines
Esterel code
loop
[ await A || await B ] ;
emit O
each R
VHDL, Verilog -> hardware implementation
Esterel design
void uart_device_driver ()
{
.....
uart.c
}
C -> software implementation
Hardware UART
Software UART
Design Specification Capture
Design
Functional
Spec
Architecture
Verification
Requirements
Editor
Project
Structure
Architecture
Diagram (2007)
Project
Management
DUT
Design
Verifier
Model
Reporter
Player
Executable
Specification
Exporter
IDE
Sequential
Equivalence
Checker
Formal
Verification

Code & Testbench
Generators
.sc
Optimized for synthesis
DFT-ready
SystemC & RTL flow integration
C / C++ / SystemC
Design
Verification
Simulator
IDE
Automatic
Documentation
Debugging &
Simulation
Editor
Sequential
Equivalence
check
.vhd
Verilog / VHDL
G. Berry, Microsoft Research
18/01/2011 31
SCADE in the Airbus A380
Anti Ice
Control Unit
–
–
–
–
–
–
–
–
–
Flight Control
Primary & Secondary
Commands
Flight
Warning
System
Flight Control system
Flight Warning system
Electrical Load Management system
Anti Icing system
Braking and Steering system
Cockpit Display system
Part of ATSU (Board / Ground comms)
FADEC (Engine Control)
EIS2 : Specification GUI Cockpit:
– PFD : Primary Flight Display
– ND : Navigation Display
– EWD : Engine Warning Display
– SD : System Display
Braking & Steering
Control Unit
G. Berry, Microsoft Research
18/01/2011 32
French Synchronous Language
Thread Level Remains High
SEVERE:
hysteresis
HIGH:
deadlock
ELEVATED:
priority inversion
GUARDED:
non-atomic action
LOW:
race condition
begin
…
end
static final void
procedure
if then else
for
while
loop
accept
case
present gift then await scream end present
Thank you Stephen Edwards
present gift then pause; every day do
await thanks end every end present
Thank you Stephen Edwards
abort nothing when bored
Thank you Stephen Edwards
every day do nothing end every
Thank you Stephen Edwards
run slowly
Thank you Stephen Edwards
await falls ; every body do
sustain disbelief end every
Thank you Stephen Edwards
present case legally do run away end present
Thank you Stephen Edwards
abort task when immediate objection
Thank you Jens Brandt
abort run slowly || run fastly when sleepy
Thank you Mike Kishinevsky
trap mouse in
every loop
do run cheese
end every
handle hair do
run water
end trap
Thank you Mike Kishinevsky
Engine control software programmed in Esterel by non-French speaker
Kavi Arya, Mumbai, 10 January 2004
Esterel
present A
then emit A
end
QEsterel
present A
then emit A
end
Thank you Georges Gonthier
Mike Kishinevsky
Mike Kishinevsky