The LDOs are on in the different modes as described in Device Functional Modes. Upon power up, the startup is shown in Figure 2.
Figure 2. Startup Diagram
Figure 3. Startup Diagram (Bridge Configuration)
After power up and the wake up (tone or command) is sent, the following steps are required to sync the DLL (Delay-Locked Loop) ramp in both direction:
- Broadcast write command to write “0x00” hex value to ECC_TEST register
- Perform auto addressing by sending a broadcast command to set CONTROL1[ADD_WRITE_EN]=1 (to enable addressing)
- Broadcast write consecutive addresses to DEVADD_USR[ADD] until all parts have been assigned a valid address
- Set the Base by writing 0 to CONFIG[STACK_DEV] of the first device
- Set the Stack by writing 1 to CONFIG[STACK_DEV] of the other device (other than first and last)
- Set Top of Stack to the top device by writing 1 to CONFIG[TOP_STACK] of the top device
- Broadcast dummy read attempts such as reading register ECC_TEST (host may not get the data)
- Clear the faults if DLL causes any COMH and COML errors.
The host must wait for the device to fully wake up ( tSU(WAKE) ) before sending shutdown, sleep, wake up commands.