8-Bit Parallel Getword Function - Texas Instruments Concerto F28M35 Series Technical Reference Manual

M-Boot ROM Description
Signal host that device is ready
Device ack read complete
The below function call sequence gives details of the flow when Parallel boot mode is selected on the
device.
• ResetIsr()
• mbrom_init_device()
• mbrom_master_system_init ()
• mbrom_control_system_init()
• mbrom_analog_system_init()
• M-Boot ROM WIR Mode Check – Please refer to WIR Mode section in the System Control and
Interrupts chapter.
• mbrom_get_bootmode()
– o Parallel_Boot();
• mbrom_start_app(M_BOOT_ROM_PARALLEL_BOOT_MODE_ENTRY_POINT)
568
ROM Code and Peripheral Booting
Figure 6-9. 8-Bit Parallel GetWord Function
Parallel_GetWordData
8 bit
(GPIO26 = 0)
Data
No
ready
(GPIO27 = 0)
?
Yes
Read word of data
from GPIO[9,8,5:0]
(GPIO26 = 1)
Host
No
ack
(GPIO27 = 1)
?
Yes
A
Copyright © 2012–2019, Texas Instruments Incorporated
A
Signal host that device
is ready to read MSB
(GPIO26 = 0)
Data
No
ready
(GPIO27 = 0)
?
Yes
Read GPIO [15:0] with
GPIO[9:8] masked into
GPIO[7:6] for LSB of data.
Discard GPIO[15:8].
Repeat for MSB of data.
Device ack read complete
(GPIO26 = 1)
Host
ack No
(GPIO27 = 1)
?
Yes
WordData = MSB:LSB
Return WordData
SPRUH22I – April 2012 – Revised November 2019
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