The BU38603, BU38703 and BU38803 are servo controller ICs for VCRs. They contain a high-speed, 8-bit CPU and perform the processing required for the drum, capstan, FV and PV completely in software, allowing a large reduction in the number of external components required. They also contain high-performance linear amplifiers, eliminating the need for interface ICs. Specialized hardware is included for items that require high-speed processing, to allow efficient utilization of the CPU.

Features
1) CPU
    499 commands (69 types)
    Memory-mapped I / O
    Minimum command execution time: 250ns (8MHz)
2)ROM capacity
    BU38603: 16384 × 8 bit
    BU38703: 24576 × 8 bit
    BU38803: 32768 × 8 bit
3) RAM capacity: 512 × 8bit
4) Interrupt
    Pattern generator: 1
    Watch-dog timer: 1
    External interrupts: 1
    FG interrupts: 5
    Internal interrupts: 7
    Two timers, serial transmission, interrupt, VHSW, CTL interval timer (fixed) / VISS
    * Multi-layer interrupts possible.
5) Free-running counter: 19 bit
6) PWM output: 12 bit × 2
7) Pattern generator
    17 bits from FRC MSB used.
    Output
        Internal: 3 bit
        External (PO): 5 bit
        External (PIO): 6 bit
8) Programmable pre-scaler
    CFG: 7 bit
    CTL: 6 bit
9) Head amplifier / chroma rotary
    Generated from pattern generator output.
10) Built-in AGC. Five-bits used to switch the gain control registers for the CTL amplifier.
11) CTL counter: 1 / 30 or 1 / 25
12) Data shift PLL calculation: 24 bit
13) Timer: 8 bit × 2
14) Synchronous serial input/output: 8 bit × 1
15) VH PULSE
    V separeted from composite synchronous snal.
    Pseudo V generated from pattern generator output.
    Superimposed pseudo H synchronized with the composite synchronous signal.
16) VISS / VASS
    VASS 0 / 1 discrimination
    VISS discrimination threshold: 3
    Aspect discrimination.
    D / A CTL switching.
17) Standard I / O
    Parallel I / O (PIO): 32 bit
    Parallel output (PO): 6 bit
18) A / D converter: 8 bits × 8 channels
    Can be masked-programmed to be parallel inputs.
19) Watch-dog timer
    Setting period: 4
20) Linear circuits
    DFG: amplifier / comparator
    CFG: amplifier / comparator
    CTL: differential amplifier / comparator
    DPG: comparator

Applications
    VHS VCRs and camcorders