BU34675

Optical disc ICs Single-chip 4-bit microcontroller for CD-DA BU34675 The BU34675 is a compact 4-bit, single-chip microcontroller that includes all the I / O required for CD system control. Circuits on the chip include a pulse width measurement counter (PWC), SIO, and an LCD controller / driver for a 28-segment display. The LCD segments can all be switched in software to CMOS output, and the extensive I / O allows many functions with a low pin count. FApplications Portable CD-DA, CD / radio / cassette players FFeatures 1) Low-voltage, high-speed operation (VDD = 2.3 to 5.5V at 4.4MHz). 2) Pulse width measurement counter on chip (for remote control reception). 3) SIO provided for communication with the DSP. 4) Seven-segment, four-common LCD controller / driver on chip. 5) All segments of the LCD controller / driver output can be switched to CMOS output using software. FAbsolute maximum ratings (Ta = 25_C) FRecommended operating conditions (Ta = 25_C) 569 Optical disc ICs FBlock diagram BU34675 570 Optical disc ICs FPin descriptions BU34675 571 Optical disc ICs FInput / output circuits BU34675 572 Optical disc ICs FElectrical characteristics (unless otherwise noted, Ta = 25_C and VDD = 5V) BU34675 573 Optical disc ICs FElectrical characteristics (unless otherwise noted, Ta = 25_C and VDD = 3V) BU34675 574 Optical disc ICs FExplanation of the hardware (1) Operates of a single power supply (VDD = 2.3 to 5.5V). (2) Memory size ROM: 6144 8 bits RAM: 256 4 bits...