hi i'm new to this site.How am i find MCU+PPM files. bcoz for 6600 5.53 latest firmware it coming with exe. when i extract it it showing like this.ex

NHL105530.01 up to 96 (NHL105530.96) and
NHL105530.A1 up C1 (NHL105530.C1)

Can someone help me to find what is MCU and PPM?.Is there any easy way to find MCU and PPM.