UM10562 Datasheet, PDF (874/942 Pages) NXP Semiconductors – LPC408x/407x User manual

NXP Semiconductors
UM10562
Chapter 38: LPC408x/407x Flash memory
"OK<CR><LF>" string is sent to the host. The host should respond by sending the crystal
frequency (in kHz) at which the part is running. For example, if the part is running at 10
MHz, the response from the host should be "10000<CR><LF>". "OK<CR><LF>" string is
sent to the host after receiving the crystal frequency. If synchronization is not verified then
the auto-baud routine waits again for a synchronization character. For auto-baud to work
correctly in case of user invoked ISP, the CCLK frequency should be greater than or equal
to 10 MHz.
For more details on Reset, PLL and startup/boot code interaction see Section 3.10.1 “PLL
and startup/boot code interaction”.
Once the crystal frequency is received the part is initialized and the ISP command handler
is invoked. For safety reasons an "Unlock" command is required before executing the
commands resulting in flash erase/write operations and the "Go" command. The rest of
the commands can be executed without the unlock command. The Unlock command is
required to be executed once per ISP session. The Unlock command is explained in
Section 38.7 “ISP commands” on page 881.
UM10562
User manual
All information provided in this document is subject to legal disclaimers.
Rev. 1 — 13 September 2012
© NXP B.V. 2012. All rights reserved.
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