[E3-hacking] PBL V5.1

[David Given]

Neil Stainton wrote:
> Sorry if this has been covered before, but can't the NOR flash be read
> or rewritten simply by bit banging the memory bus via JTAG? The JTAG
> port on the POMAP5910JGDY is IEEE 1149 compliant which I take to mean
> that all the I/O on the device can be manually overidden.
> 
> Is the JTAG port brought out to a handy set of pads somewhere? If not,
> are the appropriate balls brought out to vias underneath the CPU?

Yup, this is perfectly possible, and I believe that there are some handy 
pads inside. (If you brick the device this is the only way of fixing it.)

However, in order to reflash it, you have to take the lid off, do some 
soldering, and apply some technical knowledge --- which means that it's 
not going to be suitable for mass production. Reflashing using PBL, 
though, only requires plugging a jack in the back of the machine.

-- 
David Given
dg at cowlark.com