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UM10503
All information provided in this document is subject to legal disclaimers.
© NXP B.V. 2015. All rights reserved.
User manual
Rev. 2.1 — 10 December 2015
58 of 1441
NXP Semiconductors
UM10503
Chapter 5: LPC43xx Boot ROM
For details on secure booting using the AES engine, see
Chapter 7 “LPC43Sxx Boot ROM for secure parts”
Fig 16. Boot process for parts without flash
RESET
disable
IRQ &
MPU
CPU clock
= IRC
12MHz
check BOOT _SRC
AES
capable and
key1
programmed?
ISP pin
P2_7
LOW ?
load AES
key
yes
enter ISP
mode (USART0)
yes
UART0
boot
SPIFI
boot
check pins
P2_9,P2_8,P1_2,
P1_1
= 0
=0
EMC 8b
boot
EMC 32b
boot
EMC 16b
boot
= 1
>10
enable
JTAG
no
no
valid
Header?
yes
yes
no
AES
capable?
yes
valid
encrypted
header
and image
hash
authentic
decrypt image to SRAM
at 0x1000 0000
yes
set program counter
= 0x1000 0000,
run
copy image to
SRAM at
0x1000 0000
Reset
no
=1..4
CPU clock
=
96MHz
=2..5
>9
set program counter
= 0x1000 0000,
run
set program counter
= boot address,
run
UART3
boot
=6... 9
USB0
boot
USB1
boot
BOOT _SRC=6
or pins =5
BOOT _SRC=7
or pins =6
BOOT _SRC=9
or pins =8
BOOT _SRC=2
or pins =1
BOOT _SRC=3
or pins =2
BOOT_SRC=4
or pins =3
BOOT_SRC=5
or pins =4
BOOT_SRC=1
or pins =0
valid
Header?
yes
no
60s timeout
toggle pin
P1_1
Header
present?
AES
capable and
key1
programmed?
yes
no
no
yes
no
no
AES key1
programmed?
BOOT _SRC=8
or pins =7
SPI
(SSP)
boot