UM10462
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© NXP B.V. 2016. All rights reserved.
User manual
Rev. 5.5 — 21 December 2016
400 of 523
NXP Semiconductors
UM10462
Chapter 20: LPC11U3x/2x/1x Flash programming firmware
In case a CRP mode is enabled and access to the chip is allowed via the ISP, an
unsupported or restricted ISP command will be terminated with return code
CODE_READ_PROTECTION_ENABLED.
20.12.1 ISP entry protection
In addition to the three CRP modes, the user can prevent the sampling of pin PIO0_1 for
entering ISP mode and thereby release pin PIO0_1 for other uses. This is called the
NO_ISP mode. The NO_ISP mode can be entered by programming the pattern
0x4E69 7370 at location 0x0000 02FC.
The NO_ISP mode is identical to the CRP3 mode except for SWD access, which is
allowed in NO_ISP mode but disabled in CRP3 mode. The NO_ISP mode does not offer
any code protection.
CRP2
Yes
High
No
No
NA
CRP2
Yes
Low
No
Yes
No
CRP3
Yes
x
No
No
NA
CRP1
No
x
No
Yes
Yes
CRP2
No
x
No
Yes
No
CRP3
No
x
No
Yes
No
Table 364. ISP commands allowed for different CRP levels
ISP command
CRP1
CRP2
CRP3 (no entry in ISP
mode allowed)
Unlock
yes
yes
n/a
Set Baud Rate
yes
yes
n/a
Echo
yes
yes
n/a
Write to RAM
yes; above 0x1000 0300
only
no
n/a
Read Memory
no
no
n/a
Prepare sector(s) for
write operation
yes
yes
n/a
Copy RAM to flash
yes; not to sector 0
no
n/a
Go
no
no
n/a
Erase sector(s)
yes; sector 0 can only be
erased when all sectors are
erased.
yes; all sectors
only
n/a
Blank check sector(s)
no
no
n/a
Read Part ID
yes
yes
n/a
Read Boot code version yes
yes
n/a
Compare
no
no
n/a
ReadUID
yes
yes
n/a
Table 363. Code Read Protection hardware/software interaction
…continued
CRP option
User Code
Valid
PIO0_1 pin at
reset
SWD enabled
LPC11Uxx
enters USB or
UART ISP
mode
partial flash
update in ISP
mode