BU34440 Datasheet | ROHM

Optical disc ICs Single-chip 4-bit microcontroller for CD-DA The BU34440 is a single-chip 4-bit microcontroller designed for CD-DA and contains parallel I / O, serial I / O, timer / counter and all other functions required for CD control in a single pact package. FApplications Portable CD-DA devices, portable CD stereos FPin assignments FFeatures 1) Low-voltage, high-speed operation (VDD=2.3 X 5.5V at 4.4MHz). 2) 4k byte ROM, 256 nibble RAM. 3) Internal 8-bit SIO (LSB first). 4) 14 programmable pull-up input / outputs. 5) 5 programmable pull-up inputs. FAbsolute maximum ratings (Ta = 25_C) FRemended operating conditions (Ta = 25_C) Optical disc ICs FBlock diagram Optical disc ICs FPin descriptions Optical disc ICs FInput / output circuits Optical disc ICs FElectrical characteristics (unless otherwise noted, Ta = 25_C, VDD = 5V) Optical disc ICs FElectrical characteristics (unless otherwise noted, Ta = 25_C, VDD = 3V) Optical disc ICs FHardware descriptions (1) Operates on a single power supply (VDD=2.3 X 5.5V). (2) Memory size ROM: 4096 8 bits RAM: 256 4 bits (3) Instruction execution time (1 cycle instruction) 1.5µsec: (at 4MHz) (4) Subroutine nesting : 8 levels (5) Interrupts: 4 factors External: 2 factors Internal (timer / counter, serial I / O) : 2 factors (6) ROM data table function (data table area : 4k B) (7) Two energy-saving modes (STOP / HALT) (8) Internal 8-bit timer counter (9) Internal serial I / O, simplifying interface with attached LSIs (LSB first) (10) 14 programmable pull-up input / outputs (11) 5 programmable pull-up inputs FExternal dimensions (Units:...