LEON3MP
reference design for the Nuhorizons Spartan3 board
Introduction
The
LEON3MP is a generic reference
design for LEON3-based systems. This version is specially adapted for
the Nuhorizons Spartan3 evaluation board, and contains the following
functionality:
- 1 -
4 LEON3 processor
cores with MP support
- Multi-processor
debug support unit (DSU) for LEON3
- 16-bit
PROM controller
- 32-bit SDRAM controller (inverted clock)
- Round-robin
AHB arbiter/controller
- AHB/APB bridge with
plug&play support
- Multi-processor
interrupt controller
- 32-bit modular timer
unit
- 1 -
2 UARTs with FIFO
- 10/100 ethernet MAC
- CAN interface
- Serial debug
communication link
- Etherner debug
communication link
- JTAG debug communication link
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The LEON3MP-Nuhorizons design is provided together with GRLIB, and is
located in grlib/designs/leon3-nuhorizons-3s1500.
Reference
architecture
The
LEON3MP is made up by cores from the GRLIB IP library, which are
connected together via the AMBA AHB and APB buses. The plug&play
configuration method of GRLIB makes it possible to assign any
combination of addresses and interrupts to the cores. However, to be
software compatible with simple operating systems such as the LEON
Bare-C cross-compiler, some of the vital cores must be assigned to
predefined addresses and interrupts. The table below shows the
reference assigment in the LEON3MP design:
Core |
Memory area
|
Interrupt |
PROM/SRAM controller
|
0x00000000 -
0x00400000 : 4 Mbyte 16-bit flash PROM
|
- |
SDRAM controller |
0x40000000 - 0x48000000 : 16 Mbyte 32-bit SDRAM
0xFFF00100 - 0xFFF00200: SDRAM controll register
|
|
APB bridge
|
0x80000000 -
0x80100000 : APB bus
|
- |
UART |
0x80000100 - 0x80000200 : UART1
registers |
2
|
Interrupt controller
|
0x80000200 - 0x80000300 : IRQ
registers
|
- |
Timer unit
|
0x80000300 - 0x80000400 : timer
registers
|
8, 9
|
LEON3 debug support
unit (DSU)
|
0x90000000 -
0xA0000000 : DSU registers
|
- |
Additional (optional) IP cores are assigned addresses and interrupts as
desribed in the table below. These assignments are LEON3MP specific and
can be changed without impact on software compatibility.
Core |
Memory area
|
Interrupt |
Serial debug
communication link
|
0x80000700 - 0x80000800 : AHB UART
registers |
- |
Ethernet debug
communication link
|
-
|
- |
JTAG debug
communication link |
-
|
-
|
10/100 Mbit ethernet MAC
|
0xFFFB0000 - 0xFFFB1000 :
ethernet
control registers
|
12 |
CAN interface |
0xFFFC0000 - 0xFFFC1000 : CAN
control registers |
13 |
On-chip RAM
|
0xA0000000 - 0xA0100000 : On-chip
RAM
|
|
UART |
0x80000900 -
0x80000A00 : Secondary UART
|
3 |
Configuration
The configuartion of
the LEON3MP design is defined through the config package located config.vhd.
This file can be automatically generated using a GUI based on tkconfig.
To launch the GUI, do 'make xconfig'. After the configuration is
completed, save and
exit the tool and config.vhd will be created automatically.

Figure 1. LEON3MP configuration GUI
The
design is pre-configured in a suitable manner for the Nuhorizons board.
A special 16-prom controller (nuhosp3.vhd) is used to access the 16-bit
flash, and can be extended to access other on-board units. The sdram
controller uses an inverted clock because the board has no clock
feed-back to phase-ajust the sdram clock. This limits the frequency to
about 40 MHz, and the 50 MHz board oscillator is multiplied with 4/5 by
an on-chip DCM to generate this frequency.
Simulation
To
simulate the testbench, first compile the model for simulation. This
can be done automatically for three different simulators. Execute one
of the following commands:
- make vsim
- make ncsim
- make ghdl
For vsim,
start the simulation with 'vsim testbench' and do 'run 100'. This
should print the current LEON3MP configuration:
$ vsim
-c -quiet testbench
Reading
/usr/local/model58/tcl/vsim/pref.tcl
Reading
/home/jiri/modelsim.tcl
# 5.8
#
VSIM 1> run
# LEON3 Demonstration design
# GRLIB Version 0.13
# Target technology: virtex2 , memory library: virtex2
# ahbctrl: mst0: Gaisler
Research Leon3 SPARC V8
Processor
# ahbctrl: mst1: Gaisler
Research AHB Debug UART
# ahbctrl: mst2: Gaisler
Research Fast 32-bit PCI
Bridge
# ahbctrl: mst3: Gaisler
Research AMBA DMA controller
# ahbctrl: mst5: Gaisler
Research OC ethernet AHB
interface
# ahbctrl: slv0: Gaisler
Research Simple SRAM
Controller
# ahbctrl: memory at 0x00000000,
size 16 Mbyte, cacheable, prefetch
# ahbctrl: memory at 0x40000000,
size 16 Mbyte, cacheable, prefetch
# ahbctrl: slv1: Gaisler
Research AHB/APB Bridge
# ahbctrl: memory at 0x80000000,
size 1 Mbyte
# ahbctrl: slv2: Gaisler
Research Leon3 Debug Support
Unit
# ahbctrl: memory at 0x90000000,
size 256 Mbyte
# ahbctrl: slv4: Gaisler
Research Fast 32-bit PCI
Bridge
# ahbctrl: memory at 0xe0000000,
size 256 Mbyte
# ahbctrl: I/O port at 0xfff80000,
size 128kbyte
# ahbctrl: slv5: Gaisler
Research OC ethernet AHB
interface
# ahbctrl: I/O port at 0xfffb0000,
size 4kbyte
# ahbctrl: slv6: Gaisler
Research OC CAN AHB interface
# ahbctrl: I/O port at 0xfffc0000,
size 4kbyte
# ahbctrl: slv7: Gaisler
Research Generic AHB SRAM
module
# ahbctrl: memory at 0xa0000000,
size 1 Mbyte, cacheable, prefetch
# ahbctrl: AHB arbiter/multiplexer rev 1
# ahbctrl: Common I/O area at 0xfff00000, 1 Mbyte
# ahbctrl: Configuration area at 0xfffff000, 4 kbyte
# apbctrl: APB Bridge at 0x80000000 rev 1
# apbctrl: slv1: Gaisler
Research Generic UART
# apbctrl: I/O ports at 0x80000100,
size 256 byte
# apbctrl: slv2: Gaisler
Research Multi-processor
Interrupt Ctrl.
# apbctrl: I/O ports at 0x80000200,
size 256 byte
# apbctrl: slv3: Gaisler
Research Modular Timer Unit
# apbctrl: I/O ports at 0x80000300,
size 256 byte
# apbctrl: slv4: Gaisler
Research Fast 32-bit PCI
Bridge
# apbctrl: I/O ports at 0x80000400,
size 256 byte
# apbctrl: slv5: Gaisler
Research AMBA DMA controller
# apbctrl: I/O ports at 0x80000500,
size 256 byte
# apbctrl: slv7: Gaisler
Research AHB Debug UART
# apbctrl: I/O ports at 0x80000700,
size 256 byte
# ahbram7: AHB SRAM Module rev 1, 2 kbytes
# can_oc6: Opencores CAN MAC, rev 0, irq 13
# eth_oc5: Wishbone/AHB interface for OC ethernet MAC, irq 12
# eth_oc5: Opencores 10/100 Mbit ethernet MAC, rev 0
# pci_mtf4: 32-bit PCI/AHB bridge rev 0, 2 Mbyte PCI memory BAR,
8-word FIFOs
# dmactrl5: 32-bit DMA controller & AHB/AHB bridge rev 0
# gptimer3: GR Timer Unit rev 0, 16-bit scaler, 1 32-bit timers, irq 8
# irqmp: Multi-processor Interrupt Controller rev 1, #cpu 1
# apbuart1: Generic UART rev 1, irq 2
# srctrl0: 32-bit PROM/SRAM controller rev 0
# ahbuart7: AHB Debug UART rev 0
# dsu3_2: LEON3 Debug support unit
# leon3_0: LEON3 SPARC V8 processor rev 0
# leon3_0: icache 1*4 kbyte, dcache 1*4 kbyte
VSIM 2>
run -all
# # **** GRLIB system test starting ****
# Leon3 SPARC V8 Processor
# register file
# multiplier
# radix-2 divider
# cache system
# Multi-processor Interrupt Ctrl.
# Generic UART
# Modular Timer Unit
# Test passed, halting with IU error mode
#
# ** Failure: *** IU in error mode, simulation halted ***
# Time: 669213500 ps Iteration: 1 Process: /testbench/iuerr File: testbench.vhd
# Break at testbench.vhd line 263
# Stopped at testbench.vhd line 263
Synthesis
To
synthesize and place&route, use the make utility and issue either 'make ise' or 'make ise-synp' to
use the XST or Synplify tools respectively.
Alternatively, the design can be implemented using
the graphical XGrlib tool, which is started with 'make xgrlib'.
Figure 2. XGrlib
implementation tool
To program the fpga, issue 'make ise-prog-fpga'. To re-program the configuration proms, do 'make ise-prog-prom'.
After programming the proms, power-cycle the board to re-load the fpga.
To get
started quicker, suitable leon3mp.bit and leon3mp.msk files are provided in the bitfiles
directory. The fpga or
configuration proms can be programmed directly with this configuration,
using the following commands: 'make ise-prog-fpga-ref' or 'make
ise-prog-prom-ref '.
Software
development
To
develop RTEMS applications, download and install the LEON3 RTEMS
Cross-compiler from gaisler.com. The LEON3 bsp automatically
detects
the location of UARTs, timers, interrupt controller and ethernet core
using the plug&play information.
A LEON3 bare-C compiler
is also available for download from gaisler.com. Both the RTEMS
and the bare-C compilers now come with full source code for both the
low-level I/O routines as well as the mkprom prom builder. This should
allow users to adapt the run-time to their own needs. All sources are
provided under GNU GPL, contact Gaisler
Research for commercial licenses of this software.
A Leon3 port of uClinux and linux-2.6.11 is available in the snapgear
linux distribution.
Debugging
The
on-chip debug support unit (DSU) makes debugging of target hardware
relatively easy. The
design support both serial, ethernet and JTAG debug interface, and the GRMON debug
monitor can be attached with a serial cable, over a LAN, or using the Xilinx JTAG programming cable. Note that when you use the ethernet or the JTAG
interface, you need specify the frequency of the AHB clock since it is
not auto-detected. Below
is a log from a debug session.
$jiri@home:~$ grmon -u -grlib -jtag -freq 40
GRMON - The LEON multi purpose monitor v1.0.9
Copyright (C) 2004, Gaisler Research - all rights reserved.
For latest updates, go to http://www.gaisler.com/
Comments or bug-reports to grmon@gaisler.com
GRLIB DSU Monitor backend 1.0.2 (professional version)
using JTAG cable on parallel port
initialising .............
Component
Vendor
Leon3 SPARC V8 Processor Gaisler Research
AHB Debug
UART
Gaisler Research
AHB Debug JTAG
TAP
Gaisler Research
AHB interface for 10/100 Mbit MA Gaisler Research
Nuhorizons Spartan3 I/O interfac Gaisler Research
AHB/APB
Bridge
Gaisler Research
Leon3 Debug Support Unit Gaisler Research
32-bit PC133 SDRAM Controller Gaisler Research
AHB interface for 10/100 Mbit MA Gaisler Research
CAN
controller
Gaisler Research
Generic APB
UART
Gaisler Research
Multi-processor Interrupt Ctrl Gaisler Research
Modular Timer
Unit
Gaisler Research
Use command 'info sys' to print a detailed report of attached cores
grmon[grlib]> inf sys
00.01:003 Gaisler Research Leon3 SPARC V8 Processor (ver 0)
ahb master 0
01.01:007 Gaisler Research AHB Debug UART (ver 0)
ahb master 1
apb: 80000700 - 80000800
baud rate 115200, ahb frequency 40.00
02.01:01c Gaisler Research AHB Debug JTAG TAP (ver 0)
ahb master 2
03.01:005 Gaisler Research AHB interface for 10/100 Mbit MA (ver 0)
ahb master 3
00.01:02b Gaisler Research Nuhorizons Spartan3 I/O interfac (ver 0)
ahb: 00000000 - 00400000
16-bit prom @ 0x00000000
01.01:006 Gaisler Research AHB/APB Bridge (ver 0)
ahb: 80000000 - 80100000
02.01:004 Gaisler Research Leon3 Debug Support Unit (ver 0)
ahb: 90000000 - a0000000
AHB trace 64 lines, stack pointer 0x00000000
CPU#0 win 8, hwbp 4, itrace 64, V8 mul/div, lddel 1
icache 2 * 4 kbyte, 32 byte/line lru
dcache 2 * 4 kbyte, 32 byte/line lru
03.01:009 Gaisler Research 32-bit PC133 SDRAM Controller (ver 0)
ahb: 40000000 - 48000000
ahb: fff00100 - fff00200
32-bit sdram: 1 * 16 Mbyte @ 0x40000000, col 8, cas 2, ref 15.6 us
05.01:005 Gaisler Research AHB interface for 10/100 Mbit MA (ver 0)
irq 12
ahb: fffb0000 - fffb1000
06.01:019 Gaisler Research CAN controller (ver 0)
irq 13
ahb: fffc0000 - fffc1000
01.01:00c Gaisler Research Generic APB UART (ver 1)
irq 2
apb: 80000100 - 80000200
baud rate 38400, DSU mode
02.01:00d Gaisler Research Multi-processor Interrupt Ctrl (ver 2)
apb: 80000200 - 80000300
03.01:011 Gaisler Research Modular Timer Unit (ver 0)
irq 8
apb: 80000300 - 80000400
8-bit scaler, 2 * 32-bit timers, divisor 40
grmon[grlib]> lo /opt/sparc-elf/src/examples/stanford
section: .text at 0x40000000, size 61200 bytes
section: .data at 0x4000ef10, size 2080 bytes
total size: 63280 bytes (222.1 kbit/s)
read 197 symbols
entry point: 0x40000000
grmon[grlib]> run
Starting
Perm Towers Queens
Intmm Mm Puzzle
Quick Bubble Tree FFT
34
50 34
34 900
316 34
50 217 1083
Nonfloating point composite is 114
Floating point composite is 857
Program exited normally.
grmon[grlib]>
The LEON3MP test bench includes memory models of both boot-prom, sram
and sdram. To build memory images for these models, do 'make soft' .
Note: this will require that the bare-C compiler for LEON3 is
installed,
and /opt/sparc-elf/bin is added to the PATH.
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