Can all ARM7s have their contents downloaded with jtag?

[rigrunner]

Hello everyone,

I'm used to having to grab rom data from proms of one type or another, so this is a new area for me.

I've got a device here with an AT91R40008 on it which i'd like to take a look at the rom data. It doesn't have any obvious jtag interface so i'll need to pick up any necessary connections from the chip.

Is it a straight forward task to hook up a jtag to this and down/upload with it or are there different tricks and tips for each chip depending on its circuit?

[andersm]

Unless I'm terribly mistaken, the AT91R40008 is romless, so just desolder the external rom and read them out with your prommer. As a general rule, any chip with internal rom will have security mechanisms to prevent reading out the contents via debug/programming interfaces.

[rigrunner]

Thanks for the info.

An external rom should make it much easier