SEGA SATURN DEVELOPER'S MANUAL

5. CD block structure: The features and logical structure of the CD block as seen from the host are shown below.
(1) Data format: The CD buffer manages the stream in fixed-length (2352 bytes) sector units regardless of the device.
However, the effective data length in one sector does not necessarily match 2352 bytes for input / output with the device. For the host, a variable length between 2048 and 2352 bytes can be set.
(2) Stream selection circuit: The function to separate and store the stream is realized by a mechanism called aperture / buffer partition. These functions are regarded as logical elements (selectors). By combining selectors, construct a circuit that selects the required stream.
(3) Device: CD and MPEG are regarded as logical devices that generate and absorb streams. The flow of the stream is controlled by connecting a device to the stream selection circuit.
5.1 Data flow: The overall data flow for the CD block is shown in Figure 5.1.

Figure 5.1 Data flow of the entire CD block

5. CD block structure