Ganged SelectMAP Configuration - Ganged SelectMAP Configuration - UG570

It is also possible to configure multiple devices simultaneously with the same configuration bitstream by using a ganged SelectMAP configuration. In a ganged SelectMAP arrangement, the CSI_B pins of two or more devices are connected together (or tied to ground), causing all devices to recognize data presented on the D pins.

All devices can be set for slave SelectMAP mode if an external oscillator is available as illustrated in the following figure, or one device can be designated as the master device.

Notes relevant to the previous figure:

1. The DONE pin is by default an open-drain output. See Configuration Pin Definitions for DONE signal details.
2. The INIT_B pin is a bidirectional, open-drain pin. An external pull-up resistor is required.
3. See Figure 1 for a more detailed view of the slave SelectMAP connections

If one device is designated as the master, the DONE pins of all devices must be connected. The DONE pin is by default an open-drain output. See Configuration Pin Definitions for DONE signal details. Designers must carefully focus on signal integrity due to the increased fanout. Signal integrity simulation is recommended.

Readback is not possible if the CSI_B signals are tied together, because all devices simultaneously attempt to drive the data signals.