Ds80249 P Rev 12 Schematic __full__ Instant

An alternate host‑controlled sequence allows the application to decide exactly when the clock starts, using RSTIN and CMDVCC together. The schematic must properly wire and CMDVCC to host GPIO pins to support both activation methods.

| | Check on Rev 12 Schematic | |------------------------------------------|------------------------------------------------------| | Card present not detected | Pull-ups on PRES line; debouncing caps C_DET1, C_DET2| | I/O data errors at high baud rates | Length of I/O trace; missing 330Ω series resistor | | Card resets immediately after activation | RST_IN timing capacitor (C_RST – 0.1µF to GND) | | VPP measures 0V during programming | Charge pump flying caps polarity; VPP_EN resistor | | Excessive heat on IC | Missing ground vias under thermal pad (Pin 0) | ds80249 p rev 12 schematic

Connect a current-limited DC power supply to the main input. Use a digital multimeter (DMM) to check voltages at designated test points (TP) indicated on the schematic: Use a digital multimeter (DMM) to check voltages