OTP program memory locks the firmware at the factory
The B505CA4EMCAXP carries 32 KB of one-time-programmable (OTP) memory — the program is written during manufacturing and cannot be erased or updated in the field. This suits high-volume, firmware-fixed applications where code changes after deployment are not part of the product lifecycle. The C500 core runs at 20 MHz, a 8-bit architecture with 1.25K x 8 of on-chip RAM for data buffering and stack operations. The 34 general-purpose I/O lines are brought out through a 44-pin QFP (PG-MQFP-44-2) package, surface-mount for automated assembly.
Peripheral set and supply rail for 5V legacy systems
On-chip peripherals include a power-on reset (POR), pulse-width modulation (PWM) outputs, and a watchdog timer (WDT). An 8-channel, 10-bit analog-to-digital converter handles analog inputs without an external ADC. The oscillator is external; the device does not include an internal RC clock. A crystal or ceramic resonator must be provided on the PCB.