Paraflasher

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THIS PAGE IS STILL UNDER CONSTRUCTION AND IS NOT LINKED ANYWHERE YET

Welcome to The LPCflasher Project. Open source hardware for developing open source software.

The project is maintained by Joseph Smith.

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Overview

The LPCflasher is low-cost simple flash programming device. It can be used to flash a variety of LPC flash chips and firmware hubs (FWH). The hope is someday it will also be able to support SPI chips. It is also meant to be modular so you can flash a variety flash chip packages. The LPCflasher is based on an old LPC programmer built to flash LPC chips on the xbox, the LPC^2 (Low Parts Count LPC Programming Cable). The LPCflasher is not for sale, it is meant for that "do-it-yourself" kind of person. Although if the project becomes popular, bare PCB's could be produced and sold at cost. Anyone with novice to moderate soldering skills can build one.

Other Pictures

Components

Component Recomended Specs Part Used Price Paid ($US)
DB25 Connector
  • Type:D Sub
  • No. of Contacts:25
  • Gender:Plug
  • Contact Termination:Right Angle Through Hole
ITW McMurdo DB25PNF 3.82
10-Bit FET Bus Switch With Level Shifting
  • Package/Case:SOIC (DW)
  • No. of Contacts:24
  • Supply Voltage (Min/Max):4.5V/5.5V
  • Supply Current (Max):3uA
Texas Instruments SN74CBTD3861DW 0.64
SOIC To DIP Adapter
  • Package/Case:28-DIP
  • No. of Contacts:28
  • SOIC Mounting Type:Surface Mount
  • DIP Mounting Type:Through Hole
  • DIP Pitch Spacing:2.54mm
MIND_TEK SOIC surface mount PCB adaptor 1.60
Octal Buffer
  • Package/Case:20-DIP
  • IC Generic Number:74HC244
  • Supply Voltage Max:6V
  • Mounting Type:Through Hole
STMicroelectronics M74HC244B1R 0.40
Header Connector
  • Gender:Header
  • No. of Contacts:16
  • Pitch Spacing:2.54mm
  • No. of Rows:2
Molex 10897162 1.19
USB B Connector
  • Gender:Receptacle
  • No. of Contacts:4
  • Connector Mounting:PC Board
  • Contact Termination:Right Angle Through Hole
Adam Technologies USB-B-S-RA 0.39
PTC Resettable Fuse
  • Hold Current:0.25 Amp (250ma)
  • Trip Current:0.5 Amp (500ma)
  • Current Rating (Max):40 Amps
Littelfuse 60R025XU 0.26
Blue LED
  • Bulb Size:5mm
  • LED Color:Blue
  • Forward Current:20mA
  • Forward Voltage:3.4V
OPTEK Technology OVLFB3C7 0.74
LED Resistor
  • Resistance:200 Ohms
  • Power Rating:2 Watts
  • Material:Metal Film
Vishay/Dale CPF2200R00FKE14 0.42
Linear Voltage Regulator
  • Voltage Regulator Type:LDO Linear
  • Output Voltage Max:3.3V
  • Package/Case:3-TO-220
  • No. of Pins:3
National Semiconductor LM1084IT-3.3/NOPB 2.83
2 Tantalum Capacitors
  • Capacitance:10 uF
  • Tolerance:10%
  • Voltage Rating:10 Volts
  • Termination Style:Axial
  • Product:Tantalum Solid High Reliability
Vishay/Sprague 173D106X9010VE3 0.56 X 2
Breadboard PCB
  • Min External Height: 50.80mm
  • Min External Width: 82.55mm
  • Board Thickness:1.5mm
  • Pitch Spacing:2.54mm
  • Hole Diameter:1mm
A piece of Roth Electronik 26M2198 Already had (5.93)
Hook-Up Wire
  • Conductor Size AWG:30
  • Jacket Material:Polyvinylchloride (PVC)
  • No. Strands x Strand Size:Solid
  • Conductor Material:Copper
About a foot of Belden 9978 013100 Already had (Spool of 100ft 22.61)
Small Power Wires
  • Red wire for 5V
  • Two Orange wires for 3.3V
Already had

The Circuit Explained

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Data Circuit

The LPCflasher is connected to the PC’s Parallel port via a DB25 Parallel extension cable and is run in SPP mode. A series of 1K ohms resistors 250mW (1/4W) on data lines D0 – D6 convert the signals from 5V to 3.3v needed by the flash chip. The parallel port data lines D0, D1, and D2 are used for driving the control signals LCLK, LFRAME, and RST. The parallel port data lines D3, D4, D5, and D6 are used for bi-directional data transfers of the corresponding LAD0, LAD1, LAD2, and LAD3 lines. LAD0, LAD1, LAD2, and LAD3 lines are also buffered and feed back to the parallel port /Error, /SELIN, /PE, and /Ack signals. The 74HC244 is an advanced high-speed CMOS Octal Bus Buffer that acts as a simple signal buffer between D0, D1, /Error, /SELIN, /PE, /Ack and the LCLK, LFRAME, LAD0, LAD1, LAD2, LAD3 lines.

M74HC244B1R

Signals Simplified

Parallel Port To LPC Signal To FWH Signal
D0 LCLK CLK
D1 LFRAME FWH4
D2 RST RP
D3 LAD0 FWH0
D4 LAD1 FWH1
D5 LAD2 FWH2
D6 LAD3 FWH3
/Error LAD0 FWH0
/SELIN LAD1 FWH1
/PE LAD2 FWH2
/Ack LAD3 FWH3

Power Circuit

I did not like the original power circuit design of using a wall-wart type power supply and a LED as voltage regulator, so I came up with the following and it works pretty slick. The LPCflasher is powered by USB via a USB printer cable. The jack is a USB type B. All of the grounds from every component requiring a ground is connected together. The +5 VDC from USB is connected to a PTC Resettable Fuse with trip current of 0.5 Amp (500ma). USB v2.0 specifies a maximum of 500mA so this will protect the PC’s USB port from any damage caused by short circuits, etc. If the PTC Resettable Fuse is tripped, disconnect the power source (USB) and wait a few seconds for the PTC Resettable Fuse to cool down and reset. Next I put in a simple LED circuit just for user aesthetics, so you know your getting power from USB. If you want to use a different color LED or if the blue LED is too bright you can adjust the ohms of the resistor. A 5V power line branches off from here and continues to the header to power a 5V flash chip. I went with the LM1084IT-3.3 voltage regulator because it is designed to convert 5V to a fixed output of 3.3V to power the octal buffer and a 3.3V flash chip. Simple and effective. National Semiconductor recommends for a 5V to 3.3v conversion to place a 10 UF Tantalum capacitor on both the input and output lines of the voltage regulator. They recommend using Tantalum capacitors for stability because their equivalent series resistance (ESR) is lowest at any temperature. The 3.3V line powers the 74HC244 octal buffer and continues on to the header to power a 3.3V flash chip.


If there are any inconsistencies or you would like to elaborate on anything above, please feel free.

Daughter Boards

TODO

Software

TODO: flashrom???

Support

TODO

Conclusion

TODO