Slave Boot Procedures
CS4953xx Hardware Users Manual
DS732UM7
Copyright 2008 Cirrus Logic, Inc
2-4
Pseudocode and flowcharts will be used to describe each of these boot procedures in detail. The flow charts use the
following messages:
•
Write_* –
Write to CS4953xx
•
Read_* – Read from CS4953xx
Please note that * above can be replaced by SPI™, I2C
®
, Intel
®
, Multiplexed Intel
®
, or Motorola
®
depending on the
mode of host communication. For each case, the general download algorithm is the same. The system designer
should also refer to the control port sections of this document in
and
for the details of when writing to and reading from the CS4953xx is valid.
One feature that is of special note – the entire boot procedure for the CS4953xx can be made of a combination of
slave boot and host-controlled master boot procedures. An example can be seen in
After completing the full download to the CS4953xx, a KICK START message is sent to cause the application code
begin execution. Please note that it takes time to lock the PLL and initialize the SDRAM interface when initially
booting the DSP. Typically this time is less than 200 ms. If a message is sent to the DSP during this time, the
SCP1_BSY pin will go low to indicate that the DSP is busy. Any messages sent when the SCP1_BSY pin is LOW
will be lost. If the SCP1_BSY pin stays LOW longer than 200 ms the host must reboot the DSP.
2.2.1 Host Controlled Master Boot
The Host Controlled Master Boot (HCMB) procedure is a sequence where the system host controller instructs the
CS4953xx to boot application code from either the external memory interface (ROM or Flash), or the serial control
interface (serial SPI Flash/EEPROM or I
2
C EEPROM). The system host controller can communicate with the
CS4953xx via SPI
™
, I
2
C
®
, or one of the three parallel formats (Intel
®
, Multiplexed Intel
®
, or Motorola
®
). The
external memory start address of the code image, as well as the data rate, are specified by the host by the
HCMB_<MODE> message. These messages are defined in
Section 2.2.3 "Boot Messages" on page 2-10
.
Содержание CS4953xx
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Страница 56: ...SPI Port CS4953xx Hardware Users Manual DS732UM7 Copyright 2008 Cirrus Logic Inc 3 22 ...
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Страница 88: ...SDRAM Flash Controller Interface CS4953xx Hardware Users Manual DS732UM7 Copyright 2008 Cirrus Logic Inc 8 10 ...
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