SelectMAP Bus Width Detect Pattern and Bit Order

The Versal adaptive SoC programmable device image (PDI) boot header is read by the RCU BootROM to determine the SelectMAP bus width. The first 16 bytes in the PDI boot header determine the SelectMAP bus width. The BootROM configures the 32-bit SMAP_IO pins and once the bus detection pattern is recognized, the BootROM un-configures any SMAP_IO MIO pins not used by the selected bus width. The JTAG_STATUS [5:4] register displays the SelectMAP bus width detected by the BootROM.

SelectMAP Bit Order

The SelectMAP interface is typically driven by a user application residing on a processor, controller, or another FPGA or SoC. For these applications, it is important to understand how the data ordering in the programmable device image corresponds to the data ordering expected by the Versal device interface. The following table shows how to load the SelectMAP PDI data bits onto the SelectMAP data pins.