Summary of Accomplishments

1
Summary of Accomplishments

• Generated an Internal Boot ROM image
• Booted Leon in simulation
• Booted Leon in Hardware
• Control software
• SDRAM
• Implemented a Leon to FPX SDRAM controllor
  interface (Currently testing)

2
Leon Boot Check
Message to user LEON READY
SRAM
data_in
data_out
Leon Boot Monitor
Z
SRAM_OE
CpuData
Leon Processor
CpuAddr
3
Boot Rom Modifications
Set Config registers
Set Config registers
Set up dedicated SRAM space
Set up dedicated SRAM space
Wait for Event
ld count 200
Wait for Event
Load ld reg value
Load ld reg value
dec count
btst 1 reg
be CheckReady
be Load
btst 1 reg
be Load
Wait for Start
CheckReady ld reg ProgAddr
cmp 0 reg
be CheckReady
nop
jmp reg
Original Leon Boot code
Modified Leon Boot code
4
Leon Control Hardware
Message to user LEON READY
SRAM
data_in
data_out
Leon Control State Machine Check for CpuAddr
CheckReady
0
LeonGo
CpuAddr
LeonGo
UserAddr
Z
LeonGo
UserStart
SRAM_OE
CpuData
UserData
Leon Processor
CpuAddr
5
Interaction with LEON

• Basic steps to interface LEON/SRAM
• Wait for LEON READY message
• Load Program to SRAM
• Send LEON START message
• Wait for LEON READY message
• Read results from SRAM

6
Goals For Next Week

• Have Leon load a simple program from SRAM
• Modify Boot Rom image
• Intergrate LEON controller state machine
• Interface to control software
• Load Program (Write SRAM)
• Start Program
• Read Results ( Read SRAM)

7
SDRAM Interface

• Implemented Adapter connecting AMBA bus with SRAM
  Controller
• Not fully tested
• Does not yet Support Burst Transfers
• Burst Transfers
• FPX SDRAM Controller Supports Burst Transfers up
  to 256 words
• Sequential Access only
• Must know the burst length at start of transfer
• AMBA protocol supports sequential and
  non-sequential bursts
• Burst Length is variable

8
SDRAM Interface

• Goals
• Insure that current adapter works in all cases
• Add support for special cases of bursting
• Support for sequential bursts of short lengths
• No burst support for writes
• Integrate into FPX wrappers

9
Control S/W Architecture
Internet web page
H/W
Java UDP Client
Java Emulator of the H/W
10
Control S/W web page
11
Java Server receiving the packet
12
Goals

• Test H/W from build.arl.wustl.edu
• Document Cross-compiler procedure
• Look into debugger, time permitting