Cirrus Logic CS4953xx, Руководство пользователя по оборудованию

Страница: 28 / 118

Slave Boot Procedures
CS4953xx Hardware Users Manual
DS732UM7 Copyright 2008 Cirrus Logic, Inc 2-12
HCMB_SPI is used when the application code is stored in external SPI ROM, either SPI EEPROM or SPI Flash.
The HCMB_SPI message should be substituted for the HCMB_<MODE> message in
Figure 2-2 . This boot mode
can be configured to interface with many types of SPI ROMs. The start address ‘A’ variable can be either 24-bit or
16-bit, configured by the ‘L’ variable. Some SPI ROMs require some ‘dummy’ bytes after the address byte, before
reading from the part, configurable by the ‘B’ variable. The SPI clock is derived from the internal core clock. This
clock can be divided down with the ‘c’ 12-bit divider variable. The command byte (the first byte to the SPI ROM)
can be defined by the ‘s’ variable. The CS4953xx control port used for the HCMB_SPI can be configured by the ‘p’
variable. Finally, the ‘S’ variable configures the chip select used, according to
Table 2-6 below.
2.2.3.5 Soft Reset
The SOFT_RESET message is the message sent to the CS4953xx after all of the overlays have been successfully
booted. The SOFT_RESET leaves execution of the bootloader and begins execution of the loaded overlays. The
overlays can be configured once the SOFT_RESET message has been sent.
2.2.3.6 Messages Read from CS4953xx
Table 2-8 defines the boot read messages, in mnemonic and actual hex value, used in CS4953xx boot sequences.
Note: There is a unique {ID} for every .uld file.
Table 2-6. GPIO Pins Available as EE_CS in HCMB
‘S’ Value Pin Name
LQFP-144
Pin #
LQFP-128
Pin #
0 GPIO20 6 38
1 GPIO23 14 46
2 GPIO25 25 -
3 GPIO0 121 14
Table 2-7. SOFT_RESET message for CS4953xx
MNEMONIC VALUE
SOFT_RESET 0x4000 0000
SOFT_RESET_DSP_A 0x5000 0000
Table 2-8. Boot Read Messages from CS4953xx
MNEMONIC VALUE
BOOT_START 0x0000 0001
BOOT_SUCCESS 0x0000 0002
APP_START 0x0000 0004
BOOT_ERROR_CHECKSUM 0x0000 00FF
INVALID_BOOT_TYPE 0x0000 00FE
BOOT_FAILURE 0x0000 00F8
APPLICATION_FAILURE 0xF0
{ID}
0000