Optical disc ICs
Single-chip 4-bit microcontroller for
CD-DA
BU34381
The BU34381 is a 4-bit microcomputer designed for CD-DA players, and has a wide array of internal I / O components,
including an 8-bit, 8-channel AD converter, pulse width counter (PWC), two serial I/ O, and an LCD controller / driver
capable of displaying up to 80 segments. All LCD segments are programmable for CMOS output. These I / O components allow for multifunction applications with a low number of pins.
FApplications
Portable CD-DA players, portable CD stereos
FFeatures
1) High speed operations and low voltage. (V
5.5V at 4.4MHz)
2) Internal 8-bit, 8-channel AD converter.
3) Internal pulse width counter.
4) Two internal serial input / outputs.
DD = 2.7 X
5) Internal 20-segment, 4-common LCD controller / driver. (usable with 3 commons)
6) All segments output by the LCD controller / driver are
programmable for CMOS output.
FAbsolute maximum ratings (Ta = 25_C)
FRecommended operating conditions (Ta = 25_C)
91
Optical disc ICs BU34381
Block diagram
92
Optical disc ICs BU34381
Pin assignments
Pin descriptions
93
Optical disc ICs BU34381
94
Optical disc ICs BU34381
Input / output circuits
95
Optical disc ICs BU34381
FElectrical characteristics (at 5V) (unless otherwise noted, Ta = 25_C, VDD = 5V)
96
Optical disc ICs BU34381
97
Optical disc ICs BU34381
FElectrical characteristics (at 3V) (unless otherwise noted, Ta = 25_C, VDD = 3V)
98
Optical disc ICs BU34381
Hardware descriptions
(1) Operates on a single power supply (V
DD = 2.7 X
5.5V)
(2) Memory size
ROM : 12288
RAM : 512
LCD display RAM: 20
8 bits
4 bits
4 bits
(3) Instruction execution time (1 cycle instruction)
1.5µsec: (at 4MHz)
(4) Subroutine nesting : 8 levels
(5) Interrupts : 6 factors
External : 3 factors
Internal (time counter, serial I / O): 3 factors
(6) ROM data table function (data table area: 12KB)
(7) Two energy-saving modes (STOP/ HALT)
(8) Internal 20-segment LCD driver adaptable for vari-
ous types of displays
Bias : 1 / 3
Duty settings : 1 / 3, 1 / 4 (programmable)
Internal bias resistor (3 stages, approx. 50kΩ)
(9) LCD segment output is program-switchable to
CMOS output
All 20 segments can be selected in 4-bit
groups
Resetting: CMOS small-current output port,
LOW polarity
(10) Internal remote control receiver (pulse width counter)
(11) Internal 8-channel, 8-bit A / D converter
(12) A / D input is programmable in 1-bit units as digital
input
(13) Internal 8-bit timer counter (also used as event
counter)
(14) Two internal serial input / outputs (LSB fast) that
simplify interface with external LSI chips
(15) 12 input / outputs (programmable pull-up)
(16) 5 inputs (programmable pull-up)
99
Optical disc ICs BU34381
External dimensions (Units: mm)
100
Loading...