Leon/grlib design and Configuration Guide

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LEON/GRLIB Guide

GRLIB VHDL IP Core Library

2018 Configuration and Development Guide

The most important thing we build is trust

GUIDE, Apr 2018, Version 2018.1

www.cobham.com/gaisler

Configuration and Development Guide

Apr 2018, Version 2018.1

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GUIDE, Apr 2018, Version 2018.1

2

www.cobham.com/gaisler

LEON/GRLIB Guide

Table of contents

1

Introduction............................................................................................................. 4

1.1

Overview ............................................................................................................................. 4

1.2

Other Resources .................................................................................................................. 4

1.3

Licensing ............................................................................................................................. 4

2

System Design Guidelines ...................................................................................... 5

2.1

Introduction ......................................................................................................................... 5

2.2

Minimal System .................................................................................................................. 5

2.3

Memory Map....................................................................................................................... 5

2.3.1

Overview............................................................................................................... 5

2.3.2

Typical LEON/GRLIB Memory Map................................................................... 6

2.3.3

Memory Map in Systems That Need 2 GiB Memory Area .................................. 7

2.3.4

AHB I/O Area and GRLIB Plug&Play Areas....................................................... 7

2.4

Interrupt Assignments.......................................................................................................... 7

2.4.1

Overview............................................................................................................... 7

2.4.2

Linux 2.6 and later ................................................................................................ 8

2.4.3

RTEMS ................................................................................................................. 8

2.4.4

VxWorks ............................................................................................................... 8

2.5

Device Specific Identification ............................................................................................. 8

3

LEON design information....................................................................................... 9

3.1

Introduction ......................................................................................................................... 9

3.2

General Recommendations.................................................................................................. 9

3.2.1

Data Cache Snooping............................................................................................ 9

3.2.2

V7 and FPU........................................................................................................... 9

3.2.3

MMU and Supervisor Tag bit ............................................................................... 9

3.3

LEON Example Configurations .......................................................................................... 9

3.3.1

Overview............................................................................................................... 9

3.3.2

Minimal LEON Configuration............................................................................ 10

3.3.3

General Purpose LEON Configuration ............................................................... 11

3.3.4

High Performance LEON Configuration ............................................................ 11

3.3.5

Configuration Settings For Existing LEON Devices.......................................... 13

3.4

LEON subsystem (gaisler.subsys.leon_dsu_stat_base)..................................................... 13

4

Multiple Buses, Clock Domains and Clock Gating .............................................. 14

4.1

Introduction ....................................................................................................................... 14

4.2

Creating Multi-Bus Systems ............................................................................................. 14

4.2.1

Overview............................................................................................................. 14

4.2.2

GRLIB Facilities ................................................................................................. 14

4.2.3

GRLIB AMBA Plug&Play in Multi-Bus Systems.............................................. 14

4.2.4

Buses in Different Clock Domains ..................................................................... 15

4.2.5

Single AHB Bus Example................................................................................... 15

4.2.6

Multi-Bus System Example ................................................................................ 15

4.3

LEON3 Double-Clocking.................................................................................................. 16

4.3.1

Overview............................................................................................................. 16

4.3.2

LEON3-CLK2X Template Design...................................................................... 16

4.3.3

Clocking.............................................................................................................. 16

4.3.4

Multicycle Paths.................................................................................................. 17

4.3.5

Dynamic Clock Switching .................................................................................. 19

4.3.6

Configuration ...................................................................................................... 19

4.4

Clock gating ...................................................................................................................... 19

4.4.1

Overview............................................................................................................. 19

4.4.2

LEON clock gating ............................................................................................. 19

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