Monday, May 10, 2010

First look to the numerical sections !


After the analog sections I've started to look to the numerical sections !

My first try is about the SPANSION Flash memory.

Here is some PCB analysis :

This is a closeup of the Flash's BGA package soldering.

The reference is AL008D0043-01, that's the marking on the package.
Of course this reference is under NDA so no datasheet is available for us !
Anyway, this component seems to be similar with the S29AL008D flash familly, where datasheet IS available.

What we can see first, is that an upper and a lower line of ball are spare because there are no trace leaving the balls. Must be to increase the component soldering, but anyway the E7 pin is connected to GND, so this can have a function.

Next, every pin on the datasheet can be found on the PCB as the pinout is always the same on these packages. And some of the not connected pins (NC) are used to increase the number of bits in the address bus to increase the memory's size.

Here I can identify 19 address lines plus 2 lines taken from the not connected ones.
Which would give us a 21 lines address bus.

Vcc and Vss pins have been confirmed on the board with my multimeter.

Another interesting thing to see is that every pin seems to be accessible using a via hole or by scratching the PCB traces to solder something on it to get a probe (using top and bottom, I can do some more measurements if you need it).
It is a pretty thougth thing to do, but for the ones who like to play, it seems possible to strobe the all memory's busses and have it going into a FPGA for example, and logging all bus accesses !

Ok that's done !

And feel free leaving a comment or answers to the open questions of the previous articles.

1 comment:

  1. Hello, nice blog with good information! I've been doing some examination of the bluray board myself. I've been working strictly with BMD-001 boards through.

    About the flashrom, the pinout appears to be very close to standard Am29LV160D. An obvious difference is the two extra rows (mostly NC except one extra GND pin) and the B3 pad, which is NC in the Am29LV160D device, but appears to have a connection in this one.

    You say that you have identified 21 address lines, but I believe there are only 20, same as the Am29LV160D, giving it a capacity of 16Mbit. The BYTE# signal is negated, so the device uses all 16 data pins.

    The mystery B3 pin appears to be intended to be pulled to ground but the resistor has not been mounted. It gives a constant 0V reading, including when the flashrom is active and the contents are being read. And so does A3, which is supposed to be the RY/BY# signal, which is a little odd I thought...

    For my mapping of the pinout, you can have a look at

    I'm in the process of soldering wires to all pads so I can read the contents. Will see how that goes...