explanation of words

SCSP(Saturn Custom Sound Processor)

This is a multi-functional game sound source LSI that combines a PCM sound source and sound DSP.

Data (DATA)

A bit is the smallest unit that represents 0 or 1. 8 bits are collectively called a byte, and 16 bits (or 2 bytes) are called a word. When the upper and lower parts of a byte are divided into 4 bits each, each is called a nibble.

PAN-POT

Localization is a function that determines the direction and position from which sound is heard.

Direct data (DIRECT DATA)

Sound that is not passed through DSP, or without any effects applied even if it is, is called direct data (or dry data).

Effect data (EFFECT DATA)

When some effects are applied to the sound generated by the sound source section through DSP, the resulting sound is called effect data (or wet data).

MIDI standard (Musical Instrument Digital Interface)

A standard for communicating between electronic musical instruments and computers and exchanging pitches and lengths of notes.

PCM sound generator (Pulse Code Modulation sound generator)

Refers to a sound source that converts sound into PCM data and stores it in memory, then reads it from memory and outputs the sound when performing. PCM is the process of dividing sound (waveform) along the time axis and replacing each wave height value with digital data. The data obtained through this process is called PCM data.

FM(Frequency Modulation)

Refers to frequency modulation. When we talk about sound sources, we mean FM sound sources.

Linear

Represents a straight line condition. This means that the relationship between input and output is proportional. Therefore, the fact that the waveform data is linear means that the wave height value is proportional to the size of the data. This means that the quantization steps are equally spaced.

LFO(Low Frequency Oscillator)

A function generator that generates a waveform with a frequency lower than the range audible to the human ear. The waveform output of this LFO is used for modulating amplitude, frequency, etc.

DSP (Digital Signal Processor)

This is a circuit dedicated to high-speed calculations that mainly performs calculations (multiplication and addition) at high speed. The DSP built into the SCSP has specialized functions for audio, and is used as a means to produce so-called acoustic effects such as echo, reverb, chorus, and filters.

The number of samples

Indicates the number of waveform data.

dB (decibel)

This is a unit expressed using logarithms to compare the magnitude of things such as volume. Expressed in the formula,

It becomes.

Specifically, if the volume to be compared is twice the reference volume (amplitude of the waveform), the volume ratio will be 6 [dB]. Also, 1x is 0[dB], 3x is 10[dB]...
Conversely, if the volume to be compared is lower than the reference volume, this value [dB] will take a negative value. For example, if it is 1/2 times the standard, it will be -6 [dB].

Modulator

When multiple slots are connected, this refers to the slot that applies modulation. In the figure below, SLOT0 and SLOT1 are modulators.

Carrier

When multiple slots are connected, this refers to the slot on which modulation is applied. In the figure below, SLOT2 is the carrier.

┌─────┐ ┌─────┐　
│SLOT0│ │SLOT1│←Modulator
└──┬──┘ └──┬──┘　
   └─┐   ┌─┘　
    ┌┴───┴┐　
    │SLOT2│←Carrier
    └──┬──┘　
       │　

Prescaler

This function allows you to set the time required for the timer counter to increase by 1. Time selection and time specification are performed for each timer.

■Manual notation

The notation used in this manual is as follows:

Binary number

It is written with B at the end. For example, represent it as 100B. However, B may be omitted when it is 1 bit.

Hexadecimal

It is written with H at the end. For example, it is expressed as 00H, FFH.

unit

1K byte represents 1,024 bytes. 1Mbit is 1,048,576 bits.

MSB, LSB

The structure of bytes and words is such that the left side represents the upper bit (MSB, Most Significant Bit) and the right side represents the lower bit (LSB, Least Significant Bit).

undefined bit

Bits that are not defined in the sound source register or DSP register are expressed as "-". When writing data to undefined bits, write "0B".