Description

After configuring the M_AXI_GP0 (security_fssw_s0), M_AXI_GP1 (security_fssw_s1), or APB boot (security_apb) registers for TrustZone operation, the Zynq device will either hang or XMD will report "Cannot Read From Target" when using the interfaces controlled by these registers.

Solution

In order for these registers to function properly, the ACLK signal must be provided for the general purpose AXI interfaces on the Zynq Processing_System7 block.

The easiest way to accomplish this is to loop the FCLK0 clock back to the following clock nets:

• M_AXI_GP0_ACLK 
• M_AXI_GP1_ACLK
• S_AXI_GP0_ACLK
• S_AXI_GP1_ACLK