Multiple Devices in the Scan Chain

SAM-ICE can handle multiple devices in the scan chain. This applies to hardware where multiple chips are connected to the same JTAG connector. As can be seen in the following figure, the TCK and TMS lines of all JTAG device are connected, while the TDI and TDO lines form a bus.

Currently, up to eight devices in the scan chain are supported. One or more of these devices can be CPU cores; the other devices can be of any other type, but need to comply with the JTAG standard.