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

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.