The 5LP core is ARM Coretex M3.
The SIM900 is an ARM 9 core -
SIMCom presents an ultra compact and reliable wireless module-SIM900. This is a complete Quad-band
GSM/GPRS module in a SMT type and designed with a very powerful single-chip processor integrating
ARM926EJ-S core, allowing you to benefit from small dimensions and cost-effective solutions.