
UM10800
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© NXP Semiconductors N.V. 2016. All rights reserved.
User manual
Rev. 1.2 — 5 October 2016
388 of 487
NXP Semiconductors
UM10800
Chapter 25: LPC82x Flash In-System and In-Application Programming
25.7.2 Memory and interrupt use for ISP and IAP
25.7.2.1 Interrupts during UART ISP
The boot block interrupt vectors located in the boot block of the flash are active after any
reset.
25.7.2.2 Interrupts during IAP
The on-chip flash memory is not accessible during erase/write operations. When the user
application code starts executing the interrupt vectors from the user flash area are active.
Before making any IAP call, either disable the interrupts or ensure that the user interrupt
vectors are active in RAM and that the interrupt handlers reside in RAM. The IAP code
does not use or disable interrupts.
25.7.2.3 RAM used by ISP command handler
The stack of ISP commands is located at 0x1000 0270. The maximum stack usage is
540 byte and grows downwards.
25.7.2.4 RAM used by IAP command handler
The maximum stack usage in the user allocated stack space is 148 bytes and grows
downwards.
25.7.3 Debugging
25.7.3.1 Comparing flash images
Depending on the debugger used and the IDE debug settings, the memory that is visible
when the debugger connects might be the boot ROM, the internal SRAM, or the flash. To
help determine which memory is present in the current debug environment, check the
value contained at flash address 0x0000 0004. This address contains the entry point to
the code in the ARM Cortex-M0+ vector table, which is the bottom of the boot ROM, the
internal SRAM, or the flash memory respectively.
25.7.3.2 Serial Wire Debug (SWD) flash programming interface
Debug tools can write parts of the flash image to RAM and then execute the IAP call
"Copy RAM to flash" repeatedly with proper offset.
Table 342. Memory mapping in debug mode
Memory mapping mode
Memory start address visible at 0x0000 0004
Bootloader mode
0x1FFF 0000
User flash mode
0x0000 0000
User SRAM mode
0x1000 0000