STMicroelectronics lists the STM32F101T6U6 as obsolete.
36 MHz core and 32 KB Flash — what they mean for a replacement search
The 36 MHz ARM Cortex-M3 core runs control loops and protocol bridging. Pin-compatible STM32F1 devices in the 36-VFQFN package can provide larger Flash or RAM, requiring firmware rework.
