TC94A23F is a single-chip CD processor from Toshiba that incorporates a 4-bit microcontroller. The controller features an LCD/LED driver, 4-channel 6-bit AD converter, 2/3-line serial interface, buzzer, interrupt function, and 8-bit timer/counter. The CPU can select one of three crystal oscillator operating clocks (16.9344 MHz, 4.5 MHz, and 75 kHz), facilitating interface with the CD processor. The CD processor incorporates sync separation protection and interpolation, EFM decoder, error correction, digital equalizer for servo, and servo controller. The CD processor also incorporates a 1-bit DA converter. In combination with RF amp TA2153FN or TA2109F, TC94A23F can very simply configure an adjustment-free CD player. Thus, the IC is suitable for CD systems for automobiles and radio-cassette players.