UM10462
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© NXP B.V. 2016. All rights reserved.
User manual
Rev. 5.5 — 21 December 2016
396 of 523
NXP Semiconductors
UM10462
Chapter 20: LPC11U3x/2x/1x Flash programming firmware
20.10 Boot process flowchart
(1) For details on handling the crystal frequency, see
(2) For details on available ISP commands based on the CRP settings, see
.
Fig 69. Boot process flowchart
RESET
INITIALIZE
RECEIVE CRYSTAL FREQUENCY
RUN ISP COMMAND HANDLER
RUN AUTO-BAUD
CRP1/2/3
ENABLED?
WATCHDOG
FLAG SET?
CRP3/NO_ISP
ENABLED?
ENTER ISP
MODE?
(PIN PIO0_1)
USB ISP?
(PIN PIO0_3)
USER CODE
VALID?
USER CODE
VALID?
AUTO-BAUD
SUCCESSFUL?
EXECUTE INTERNAL
USER CODE
ENABLE DEBUG
yes
yes
yes
yes
yes
yes
(HIGH)
yes (LOW)
yes
no
no
no
no
no (LOW)
no
no (HIGH)
no
ENUMERATE AS MSC
DEVICE TO PC
A
A
UART
ISP
LPC11U2x/3x
only
USB ISP