UM10237,pdf datasheet (NXP Sem

NXP Semiconductor designed the LPC2400 microcontrollers around a 16-bit/32-bit
ARM7TDMI-S CPU core with real-time debug interfaces that include both JTAG and
embedded Trace. The LPC2400 microcontrollers have 512 kB of on-chip high-speed
Flash memory. This Flash memory includes a special 128-bit wide memory interface and
accelerator architecture that enables the CPU to execute sequential instructions from
Flash memory at the maximum 72 MHz system clock rate. This feature is available only
on the LPC2000 ARM Microcontroller family of products. The LPC2400 can execute both
32-bit ARM and 16-bit Thumb instructions. Support for the two Instruction Sets means
Engineers can choose to optimize their application for either performance or code size at
the sub-routine level. When the core executes instructions in Thumb state it can reduce
code size by more than 30 % with only a small loss in performance while executing
instructions in ARM state maximizes core performance.