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Copyright 2008 Cirrus Logic, Inc.
DS732UM7
Softboot
CS4953xx Hardware Users Manual
2.4.2.3 Softboot Example Steps
1.
Send the SOFTBOOT message. The host sends the SOFTBOOT message to the CS4953xx to begin overlay
swap.
2.
Wait for IRQ low. The host then waits for SCP1_IRQ (or PCP_IRQ) to go low. If the TIMEOUT period has
been reached, the host should exit. If the IRQ pin is LOW, proceed to Step 3.
3.
Read the SOFTBOOT_ACK message. If the message is the SOFTBOOT_ACK message (0x00000005), then
the host should proceed to Step 4. If the message is not the SOFTBOOT_ACK message, the host should return
to Step 2.
4.
Send the correct HCMB_<MODE> message. The host sends to the CS4953xx the appropriate
HCMB_<MODE> message, where <MODE> indicates the type of external ROM: PARALLEL, SPI, or I2C.
This message tells CS4953xx the start address of the downloadable image (.ULD file) and identifies which port
will be used to access FLASH memory.
5.
Wait for IRQ low. The host then waits for SCP1_IRQ (or PCP_IRQ) to go low.
6.
Read the BOOT_START message. If the initialization is successful, CS4953xx will send the BOOT_START
message to the host. If the message is any other value, then the host should abort.
7.
Wait for IRQ low. After receiving the BOOT_START message, the host then waits for SCP1_IRQ (or
PCP_IRQ) to go low. This indicates that the DSP has written a message to the output buffer and the boot process
is complete.
8.
Read the BOOT_SUCCESS message. The host then reads another message from the appropriate
communications port. Each.ULD file contains a checksum that is compared at the end of the boot process. The
CS4953xx sends a BOOT_SUCCESS message to the host if the checksum is correct after the download.
If the checksum was incorrect, CS4953xx responds with a BOOT_ERROR_CHECKSUM message. This
indicates that the image read by the DSP is corrupted. The communications interface hardware and code image
integrity should be checked if this occurs.
9.
Repeat Steps 4-8 for all code images/Overlays. The host repeats these steps until all overlays for the
application have been successfully loaded. See the application note for more information on the overlays
necessary at start-up.
10. Send the SOFT_RESET message. After reading the BOOT_SUCCESS message on the last code image/
overlay, the host must send a SOFT_RESET message which will cause the application code to begin executing.
11. Wait for IRQ low. The host then waits for SCP1_IRQ (or PCP_IRQ) to go low.
12. Read the APP_START message. If code execution is successful, the CS4953xx sends out an 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. If the message read
is any value other than APP_START, the system controller should abort.
13. Send Hardware Configuration messages. The master 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.
14. 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.
15. Send the KICKSTART message. The CS4953xx begins processing audio after receiving this message.
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Summary of Contents for CS4953xx
Page 34: ...Softboot CS4953xx Hardware Users Manual DS732UM7 Copyright 2008 Cirrus Logic Inc 2 18 ...
Page 56: ...SPI Port CS4953xx Hardware Users Manual DS732UM7 Copyright 2008 Cirrus Logic Inc 3 22 ...
Page 58: ...CS4953xx Hardware Users Manual DS732UM7 Copyright 2008 Cirrus Logic Inc 4 2 ...
Page 118: ...Revision History CS4953xx Hardware Users Manual DS732UM7 Copyright 2008 Cirrus Logic Inc 9 30 ...
