Selecting the Configuration Mode

Each configuration interface corresponds to one or more configuration modes and bus widths.
  • Select the configuration mode by setting the appropriate condition on the CBUS[2:0], , and input .
  • Set CBUS2, CBUS1, CBUS0, SS_N, and TEST_N using a pull-up or pull-down resistor, or drive them with an external active device.
  • Do not toggle the mode before the enters user mode.
Table 1. SPI Hardware SettingsIf you do not make any connections, the default mode is x1 SPI active.
Configuration Mode Parallel/Serial CSI CBUS2, CBUS1, CBUS0 Width
SPI Active Serial 1 1 1 3’b111 x1
Parallel 1 1 1 3’b110 x2
Parallel 1 1 1 3’b101 x4
SPI Passive Serial 1 1 0 3’b111 x1
Parallel 1 1 0 3’b110 x2
Parallel 1 1 0 3’b101 x4
Parallel 1 1 0 3’b100 x8
Parallel 1 1 0 3’b011 x16
Parallel 1 1 0 3’b010 x32

The JTAG/boundary-scan configuration interface is always available regardless of pin settings. If you send configuration instructions to the JTAG interface, the overwrites the previous configuration.

Note: You must set the configuration mode in the software; the software includes the mode and other configuration options in the bitstream.

The supported configuration modes are specific. Refer to your 's data sheet for information on the configuration modes it supports.