Function details-6

8.2.6 Buffer information

List

Title Function specifications

Function Get CD buffer size

Function Name [S-] CDC_GetBufSiz

No 6.1

Form

Sint32 CDC_GetBufSiz (Sint32 * totalsiz, Sint32 * bufnum, Sint32 * freesiz)

input

none

output

totalsiz	: Total buffer size (sector unit, 200 sectors = C8H)
bufnum	: Total number of buffer partitions (24 partitions = 18H)
freesiz	: Free buffer size (in sector units)

Function value

Returns an error code.

function

Gets the size of the entire CD buffer, the number of buffer partitions (both are fixed values), and the current free size.
The number of selectors (or the number of apertures) is equal to the total number of buffer partitions.

remarks

Even if the free size is 0, it does not necessarily mean that the buffer is full because there are sectors used by the system.

List

Title Function specifications

Function Get the number of sectors in the CD buffer partition

Function Name [S-] CDC_GetSctNum

No 6.2.

Form

Sint32 CDC_GetSctNum (Sint32 bufno, Sint32 * snum)

input

bufno: Buffer partition number

output

snum: Number of sectors in the buffer partition (buffer partition size)

Function value

Returns an error code.

function

Gets the current number of sectors in the buffer partition (buffer partition size).

List

Title Function specifications

Function Calculation of actual data size

Function Name [SR] CDC_CalActSiz

No 6.3

Form

Sint32 CDC_CalActSiz (Sint32 bufno, Sint32 spos, Sint32 snum)

input

bufno	: Buffer partition number
spos	: Sector position ( CDC_SPOS_END: Indicates the last sector of the partition)
snum	: Number of sectors (CDC_SNUM_END: Indicates the number of sectors from spos to the end of the partition)

output

none

Function value

Returns an error code.

End flag

ESEL flag

function

Calculates the actual data size (the number of words to retrieve to the host) from the specified sector range of the buffer partition. To get the calculation result, execute Get Actual Data Size (CDC_GetActSiz).
In case of error, the actual data size will be as follows.

Constant name	explanation
CDC_ACTSIZ_ERR	The calculation could not be performed.

The length of one sector can be changed by setting the sector length (CDC_SetSctLen).

remarks

The connector connected to the partition output connector is disconnected.

List

Title Function specifications

Function Get the actual data size

Function Name [S-] CDC_GetActSiz

No 6.4

Form

Sint32 CDC_GetActSiz (Sint32 * actwnum)

input

none

output

actwnum: Actual data size (number of words)

Function value

Returns an error code.

End flag

ESEL flag (only checked)

function

Acquires the calculation result (initial value 0) of the actual data size.
The result of the previous calculation is retained until the next calculation (CDC_CalActSiz).

List

Title Function specifications

Function Acquisition of sector information

Function Name [S-] CDC_GetSctInfo

No 6.5 6.5

Form

Sint32 CDC_GetSctInfo (Sint32 bufno, Sint32 spos, CdcSct * sct)

input

bufno	: Buffer partition number
spos	: Sector position ( CDC_SPOS_END: Indicates the last sector of the partition)

output

sct: Sector information

Function value

Returns an error code.

function

Acquires the header information (FAD) and subheader information of the specified sector of the buffer partition.

List

Title Function specifications

Function Performing a frame address search

Function Name [SR] CDC_ExeFadSearch

No 6.6

Form

Sint32 CDC_ExeFadSearch (Sint32 bufno, Sint32 spos, Sint32 fad)

input

bufno	: Buffer partition number
spos	: Sector position ( CDC_SPOS_END: Indicates the last sector of the partition)
fad	: Frame address

output

none

Function value

Returns an error code.

End flag

ESEL flag

function

Searches the sector from the specified sector position of the buffer partition using the frame address as a key. To get the search results, run Get Frame Address Search Results (CDC_GetFadSearch).

(1) Search direction

Search backwards in the buffer partition. (From the smaller sector position to the larger sector position)

(2) Search results

The contents to be retained as a search result are the buffer partition number, the sector position obtained by the search, and the frame address of that sector.

(3) Search conditions

If no matching FAD exists, search for the closest sector that does not exceed the specified FAD. In other words, the FAD of the search result is the maximum FAD that satisfies FAD ≤ specified FAD.
In case of error, the sector position and FAD of the search result will be the following values.

Sector position	Frame address	explanation
CDC_SPOS_ERR	0	There is no sector that meets the search conditions.
	CDC_FAD_ERR	The search could not be performed.

remarks

The connector connected to the partition output connector is disconnected.

List

Title Function specifications

Function Get frame address search results

Function Name [S-] CDC_GetFadSearch

No 6.7

Form

Sint32 CDC_GetFadSearch (Sint32 * bufno, Sint32 * spos, Sint32 * fad)

input

none

output

bufno	: Buffer partition number
spos	: Sector position
fad	: Frame address

Function value

Returns an error code.

End flag

ESEL flag (only checked)

function

The execution result of the frame address search (initial value is all 0) is acquired.
The previous search results are retained until the next search (CDC_ExeFadSearch).