SPIA_GetWordData
Yes
No
Data
Received
?
Send dummy
character
Read LSB
Data
Received
?
No
Yes
Read MSB
Return MSB:LSB
Send dummy
character
SPI_Boot
Yes
No
(0x08AA)
?
Valid
KeyValue
Enable the SPI-A clock
Set the LSPCLK to 4
Enable SPISIMOA,
SPISOMI and SPICLKA
pin functionality and enable
Set up SPI-A for
8-bit character,
Use internal SPI clock,
master mode
Use slowest baud rate (0x7F)
Relinquish SPI-A from reset
(GPIO19)
Set chip enable high
Enable EEPROM
Send read command and
start at EEPROM address
0x0000
Read KeyValue
Jump to Flash
Read LOSPCP value
Change LOSPCP
Change SPIBRR
Read SPIBRR value
Read and discard 7
reserved words
address
Read EntryPoint
Call CopyData
EntryPoint
Return
pullups on those pins
C-Boot ROM Description
606
SPRUH22I – April 2012 – Revised November 2019
Copyright © 2012–2019, Texas Instruments Incorporated
ROM Code and Peripheral Booting
Figure 6-22. Data Transfer From EEPROM Flow
Figure 6-23. Overview of SPIA_GetWordData Function