Cirrus Logic CS485xx - Manual (Page 25)

2-7 Copyright 2009 Cirrus Logic, Inc. DS734UM7
Master Boot Procedure
CS485xxr Hardware User’s Manual
Table 2-5 is a quick reference showing the different boot commands understood by the CS485xx , in
mnemonic and actual hex value, used in CS485xx boot sequences.
2.4 Master Boot Procedure
A master boot sequence is initiated immediately after the rising edge of RESET. The location of the overlay
to boot is outlined in
Table 2-1 . Once the rising edge of RESET has occurred, the CS485xx will load a single
overlay from address 0x0. It should be noted that the loaded overlay must reconfigure one of the control
ports to be slave to the bus for a system host controller to configure the part. Thus, this type of boot process
will be useful in systems without a system host controller or with a simple controller that only performs a
monitoring task. Currently this mode is not used for any applications.
Figure 2-3. Master Boot Sequence Flowchart
Table 2-5. Boot Command Messages for CS485xx
MNEMONIC VALUE DETAILED TABLE
SLAVE_BOOT 0x80000000 Table 2-2
SOFT_RESET 0x40000000 Table 2-3
Start
RESET ( Low)
RESET ( High)
Done
Set HS[4:0 ] Pins For
Operational Mode