UM10503
All information provided in this document is subject to legal disclaimers.
© NXP B.V. 2012. All rights reserved.
User manual
Rev. 1.3 — 6 July 2012
29 of 1269
4.1 How to read this chapter
This chapter applies to all LPC43xx parts. AES keys and AES functions are supported for
parts LPC43Sxx only.
The following bit is reserved for flash-based parts:
JTAG_DISABLE in the OTP memory bank 3, word 0 (bit 31).
4.2 Features
•
The OTP memory stores the following information:
–
User programmable are the boot source, the USB vendor and product ID, and the
AES keys.
–
Unused fields can be used to store other data.
•
API support for programming the OTP in Boot ROM provided.
4.3 General description
The OTP contains pre-programmed device specific information using two OTP banks. All
other 384 OTP bits must be programmed by the user.
The virgin OTP state is all zeros. A zero value can be overwritten by a one, but a one in
any of the OTP bits cannot be changed.
Programming the OTP requires a higher voltage than reading. The read voltage is
generated internally. The programming voltage is supplied via pin VPP. The OTP
controller automatically selects the correct voltage. If the VPP pin is not connected, then
the OTP cannot be programmed.
The AES keys in the OTP memory are not readable by software.
4.4 Register description
UM10503
Chapter 4: LPC43xx One-Time Programmable (OTP) memory
and API
Rev. 1.3 — 6 July 2012
User manual
Table 12.
OTP memory description (OTP base address 0x4004 5000)
OTP
bank
Word
Access
Address
offset
Size
Description
Reference
0
0
Pre-programmed; cannot
be changed by the user.
0x000
32 bit
Reserved
-
0
1
Pre-programmed; cannot
be changed by the user.
0x004
32 bit
Reserved
-
0
2
Pre-programmed; cannot
be changed by the user.
0x008
32 bit
Reserved
-