How To Build A Milksop:

Scope,

Milksop is a small (2.25"x3") device designed to:

-Read and reprogram a generic 40-pin TSOP Flash chip(such as that used by the Xm Radio and Microsoft X-Box) without requiring any soldering or, removal of the board!

-Be able to Communicate with a X-box and Xm Radio LPC Bus and to be able to make sure flash memory (programmable from a PC appear there.

The intention is to facilitate rapid and repeatable changes to the content of the flash to allow new code to be tried easily. It is hoped it will be of some use to people looking to boot linux on an X-Box or Test your Xm Radio!

The design schematics, gerbers and C & VHDL sources are being released under the GPL, others are encouraged to duplicate our design when it is proven. However, as with all GPL projects, no warrenty at all is given about the performance of this design.

Overview,



As you can see Milksop has three main interfaces:



a PC Printer Port,

a TSOP test adapter clipped over the flash (in the case of the X-Box, if you cannot afford ~$300 and a four-week wait for one of these, a set of wires to the X-box testpads well documented elsewhere.),
and an LPC header.

There are in turn three main modes it is expected to find a use:




1) The printer port can be used to program the flash on the Milksop (top arrow) (working 2002-06-16)
2) The printer port can be used to program the flash on a host motherboard via the TSOP header (middle arrow) (working 2002-06-16)
3) The flash on the Milksop can be read and written by the LPC port (up-down arrow) (working 2002-06-17)


In addition there are some handy features like automatic X-Box power cycling after updating the flash, useful for software developers.


Principles
In-system flash programming
For generic devices using TSOP flash, it is usually possible to get the rest of the devices on the bus to float their IO, either during reset or by applying appropriate levels to test pins or output enables. Milksop is generally useful in cases where there is no provision to allow flashing via the normal bus master (ie, you can't get the device CPU to do the flashing for you).

Milksop is powered entirely from the TSOP device being programmed, not only is Milksop intended to be used without removing the device, but it is intended that the device is powered.


Important note: Milksop must not be removed from the device it is programming while power is applied.


Flash device endurance

A typical modern flash device is rated for at least 100,000 erase/write cycles. That's probably more edits than you have time to test :-) For practical purposes you can send edited code to your device as many times as you like.

Physical Hardware,



Milksop uses a Xilinx XC95108 CPLD in a PQ100 package. This contains all of the logic. The other devices are there for signal conditioning of the printer port communications



Partslist
Qty Type Component ID Description part code

13
100n C101 C102 C103 C202
C203 C3 C4 C401 C402
C403 C404 C405 C406
1206 capacitors Farnell 644-316
1 330pF C2 Farnell 757-251
3 100uF 6V3 C201 C105 C106 submin electrolytic Farnell 334-9913
1
10uF 6V3
C104
Farnell 490-659


5 100R RP1 RP2 RP3 RP407 RP408 1206 quad respack Farnell 196-710
1 1K RP4 Farnell 196-770
1 4K7 RP5 Farnell 196-812
6
0R - NB ECN1
RP401 RP402 RP403
RP404 RP405 RP406
Farnell 776-579

1
33K
R101
1206 single resistor
Farnell 613-885

1
470R
R102
1206 single resistor
Farnell 613-666

4
47K
RA401..RA404
1206 10-pin octal bussed resistor net
Farnell 335-2328

1
820R - NB ECN1
RX1
1/4W 820R single resistor
Farnell 509-152


2 74HC14 U1 U2 SO-14 hex schmitt trigger Farnell 379-268
3
74LVXC4245
U401 U402 U403
Octal level converter / buffer
Farnell 642-526

1 XC95108PQ100C U201 Xilinx CPLD RS 235-8389
1 BAT42 D1 schottky diode Farnell 367-783
1 OSC20MHz OSC1 8-pin DIL can Oscillator Module Farnell 788-491
1
M29F080A90N1
U102
8Mbit flash
Farnell 333-5150

2
2SK1336
Q1 Q2
N-channel Mosfet
Farnell 353-024

1
LE30ABZ
U104
3.3V regulator
Farnell 352-9990


1 DB25M J1 Right-angle 25-way D connector male Farnell 892-440
1 HEADER8 J3 SIL 0.1" pitch header posts, 8 way Farnell 671-964

1 LED LED1 Green power LED Farnell 621-006

For More Info on this Go to http://warmcat.com/milksop

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