SEGA SATURN DEVELOPER'S MANUAL

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5.5 CD block initialization

Information content in the CD block is initialized as shown in Table 5.2 by each operation.

Table 5.2 Initialization contents of CD block

Operation
Information content

Tray opens

tray closes

soft reset

TOC / session information

initialized

TOC Lead

−

File information

initialized

−

initialized

Host information

-

-

initialized

CD block register

-

-

initialized

“-” Is unchanged

Operation Information content	Tray opens	tray closes	soft reset
TOC / session information	initialized	TOC Lead	−
File information	initialized	−	initialized
Host information	-	-	initialized
CD block register	-	-	initialized

∙ Even if you execute CD block initialization (CDC_CdInit) without specifying soft reset, none of the above information will be initialized.

(1) TOC / Session information

Information specific to the disc and is initialized only when the tray is opened.
When initialized, information is not entered.
TOC is automatically read when the tray is closed, and the information is retained.

(2) File information

Information on ISO9660 files held by the CD block file system.
When initialized, information is not entered.
∙ The host instructs the reading of file information with a command.

(3) Host information

Mainly host setting information and buffer data.
Initialize the initial value (equal to the default value).

Initialization information (CD block initialization parameters)
Playback information (playback range, maximum repeat count, current repeat notification count)
Selector information (host settings related to selectors such as aperture and buffer section)
Data in buffer, buffer partition size, free size
Retained actual data size, frame address search result, copy / move error information
Sector length setting value
MPEG related information (MPEG OFF)

(4) CD block register

Information about CD block hardware.

Interrupt factor register (initialized except DCHG flag)
For details, see "Table 3.3 Bit Configuration of Interrupt Source Register".
Internal register to control data transfer (Data transfer ends when initialized)

(5) Open / close tray

When the tray is opened, the DCHG and EFLS flags in the interrupt factor register are set to 1. The timing is before the state.
The tray opening / closing operation is the same for both command and manual operations. When tray open (CDC_CdOpen) is executed, it is initialized even if the tray does not actually open.

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