Parallel Gpio Mode Overview - Texas Instruments Concerto F28M35 Series Technical Reference Manual

M-Boot ROM Description
Return Zone1 Flash
EntryPoint
Figure 6-8 shows the transfer flow from the host side. The operating speed of the CPU and host are not
critical in this mode as the host will wait for the device and the device will in turn wait for the host. In this
manner the protocol will work with both a host running faster and a host running slower than the device.
566
ROM Code and Peripheral Booting
Figure 6-7. Parallel GPIO Mode Overview
Parallel_Boot
Initialize GP I/O MUX
and Dir registers
GPIO[9,8,5:0] = input
GPIO27 = input
GPIO26 = output
Enable pullups on
GPIO[9,8,5:0]
Valid
No
KeyValue
(0x08AA)
?
Yes
Copyright © 2012–2019, Texas Instruments Incorporated
Read and discard 8
reserved words
Read EntryPoint
address
Call
CopyData
Return
EntryPoint
SPRUH22I – April 2012 – Revised November 2019
Submit Documentation Feedback
www.ti.com