3 boot messages, 1 slave boot, 2 host-controlled master boot from parallel rom – Cirrus Logic CS4953xx User Manual
Page 24: 3 boot messages -10, Table 2-2. slave_boot message for cs4953xx -10, Table 2-3. hcmb_parallel message for cs4953xx -10, Section
Slave Boot Procedures
CS4953xx Hardware User’s Manual
DS732UM10
Copyright 2010 Cirrus Logic, Inc
2-10
APP_START message. This indicates that the code has been initialized and can accept further
configuration messages. The host should not attempt further communication with the CS4953xx until
the APP_START message has been read.
If the CS4953xx does not send an application start message, the host must return to
Step 1.
20.
Send Hardware Configuration messages. The slave boot procedure is completed. The operating
system on the CS4953xx is now ready for host configuration of hardware and software.
Hardware configuration messages are used to define the behavior of the CS4953xx’s audio ports. A
more detailed description of the hardware configurations can be found in Section x of this manual.
21.
Send Software Configuration messages.The software configuration messages are specific to each
application. The application code user’s guide for each application provides a list of all pertinent
configuration messages.
22.
Send the KICKSTART message(s). The CS4953xx application locks the PLL and begins processing
audio after receiving this message.
2.3.3 Boot Messages
The Slave Boot and Host-Controlled Master Boot procedures use a number of messages to configure and
synchronize the boot process. Please use the messages listed below when implementing the boot
process as a part of the system host controller firmware.
2.3.3.1 Slave Boot
The SLAVE_BOOT message is used when the system host controller will send each .uld file directly to the
CS4953xx. The SLAVE_BOOT message must be issued for each overlay image (.uld file) that is
downloaded to the CS4953xx. Please see
Section 2-3 "Slave Boot Sequence" on page 2-8
for more
details.
2.3.3.2 Host-Controlled Master Boot from Parallel ROM
Table 2-2. SLAVE_BOOT message for CS4953xx
MNEMONIC
VALUE
SLAVE_BOOT
0x8000 0000
Table 2-3.
HCMB_PARALLEL
Message for CS4953xx
MNEMONIC
VALUE
HCMB_PARALLEL
1110 0000 0000 0000 0000 0xxx xxyy yyMM
0000 0000 0000 AAAA AAAA AAAA AAAA AAAA
Where:
x = number of CS4953xx clocks from CS or Address change to Output
Enable
y = number of CS4953xx clocks from CS to Output Enable
M = memory width of parllel ROM = 0 for 8-bit, 1 for 16-bit
A = 20-bit external memory start address/2 for 16 bit flash.
A = 20-bit external memory start address/4 for 8 bit flash.