The MAX7221CNG+ is a compact, serial input/output common-cathode Display Driver that interface microprocessors (µPs) to 7-segment numeric LED displays of up to 8 digits. Included on-chip are a BCD code-B decoder, multiplex scan circuitry, segment and digit drivers and an 8x8 static RAM that stores each digit. Only one external resistor is required to set the segment current for all LEDs. It is compatible with SPI™, QSPI™ and MICROWIRE™ and has slew rate-limited segment drivers to reduce EMI. A convenient 4-wire serial interface connects to all common µPs. Individual digits may be addressed and updated without rewriting the entire display. It also allow the user to select code-B decoding or no-decode for each digit.