Basic SAM7 Program circuit

Development Boards MicroMod
1

I’m trying to switch to 32-bit processors and chose the Atmel SAM7 series because of it’s USB programming capability, not needing a special programmer. I have read the SAM-BA and SAM-PROG user manuals but have failed to pick up all of the required information. I have yet to understand how much circuitry is needed to just power up and flash a program. How much needs to be connected before it’ll flash? At the moment, I have the 3.3V, 1.8V, and GND nets wired. No decoupling capacitors. Pins A0-2 and TST are wired to go high for the bootloader recall. The circuit draws power from the USB link, through a 3.3V regulator and the USB data lines run directly from the USB connector to the corresponding pins on the SAM7. When connected to my Vista PC, neither SAM-PROG or SAM-BA sees it. Is there more connections that need to be made? Do I need a certain crystal? What am I missing?

When wired correctly, will my computer see it as a device or will only the Atmel software recognise it?

Thanks

2

Decoupling is essential on each supply pin.

Leon

3

Without looking at the datasheet, you need a crystal and PLL and you need to run it at a specific frequency range to allow USB. It’s all in the datasheets.

SAMBA is a painful way to do development, if that’s your plan. No debug interface means you are going to spend a whole lot of time trying to figure out why what you’ve done isn’t working.

4

Adding a JTAG connector and buying or making a JTAG interface will make things much easier.

Leon

5

I got a SAM-ICE JTAG programmer but I’m not sure which pin is Pin1. It’s on the end of the ribbon cable with the colored strip on it, but is Pin1 on the side of the connector with the bump, or the flat side?

6

Should be on the bump (key) side, unless it is non-standard.