Function details-6

8.2.6 Buffer information

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Title function specification

Function Get CD buffer size

Function Name［S-］ CDC_GetBufSiz

No 6.1

Format

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

input

none

output

total size	: Total buffer size (in sector units, 200 sectors = C8H)
bufnum	: Total number of buffer sections (24 sections = 18H)
free size	:Free buffer size (in sectors)

function value

Returns an error code.

function

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

remarks

Even if the free size is 0, there are sectors in use by the system, so the buffer does not necessarily become full.

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Title function specification

Function Obtaining the number of sectors in the CD buffer partition

Function Name［S-］ CDC_GetSctNum

No 6.2

Format

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).

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Title function specification

Function Calculating actual data size

Function Name［SR］ CDC_CalActSiz

No 6.3

Format

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

input

bufno	:Buffer section 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 (number of words when fetching to the host) from the specified sector range of the buffer partition. To obtain the calculation result, execute Get Actual Data Size (CDC_GetActSiz).
In case of an error, the actual data size will be the following value.

constant name	explanation
CDC_ACTSIZ_ERR	Could not perform calculation.

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

remarks

Any connectors already connected to the partition output connector will be disconnected.

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Title function specification

Function Obtaining actual data size

Function Name［S-］ CDC_GetActSiz

No 6.4

Format

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

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

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Title function specification

Function Get sector information

Function Name［S-］ CDC_GetSctInfo

No 6.5

Format

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

input

bufno	:Buffer section 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

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

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Title function specification

Function Executing frame address search

Function Name［SR］ CDC_ExeFadSearch

No 6.6

Format

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

input

bufno	:Buffer section 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 for a sector from the specified sector position in the buffer partition using the frame address as a key. To obtain the search results, execute Get Frame Address Search Results (CDC_GetFadSearch).

(1)Search direction

Search towards the back of the buffer compartment. (from the smallest sector position to the largest sector position)

(2)Search results

The contents retained as search results 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, searches for the closest sector that does not exceed the specified FAD. In other words, the FAD of the search result is the largest FAD that satisfies FAD≦specified FAD.
In case of an error, the sector position and FAD of the search result will have the following values.

sector position	frame address	explanation
CDC_SPOS_ERR	0	There are no sectors that meet the search conditions.
	CDC_FAD_ERR	Search could not be performed.

remarks

Any connectors already connected to the partition output connector will be disconnected.

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Title function specification

Function Obtain frame address search results

Function Name［S-］ CDC_GetFadSearch

No 6.7

Format

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

input

none

output

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

function value

Returns an error code.

end flag

ESEL flag (only checked)

function

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