CMT2187A is a low-power Sub-1G wireless transmitter SoC embedded with an enhanced 1T-8051 core, supporting 210 ~ 960 MHz, OOK/FSK/GFSK modulated wireless transmitter function. The chip is embedded with efficient single-ended PA with output power range which is adjustable from 0 to +13dBm, +13dBm only required 24mA while transmission. MCU programs are stored and run in 4KB MTP storage. The ultra-low-power ULPLDO can save CPU status, RAM data, and configuration register data in STOP mode. Users can use the dedicated 1-WIRE debugger and KEIL51 software to download and run the target debugging code directly into MTP for online simulation. The MTP has a dedicated area for burning 64-bit serial numbers (ids), making it ideal for remote control or active RFID applications while transmitting encrypted information. The chip supports main frequency clock source switching. The system starts with the built-in 24MHz HFOSC by default and optionally switch to the more accurate external 26MHz XOSC as the main frequency clock source of the system according to the MTP burning configuration. The built-in low-power RC oscillator 32kHz LFOSC allows the MCU to perform low-power timed wake-up. HFOSC and LFOSC are calibrated to ±1% accuracy at the factory, and can also be calibrated by calling API functions to access the correction circuit module while using.