# DC_Unlockdown

## Syntax

      #include <nitro/os.h>

      void DC_Unlockdown( u32 num );

## Arguments

num | Designates the number of lockdown blocks to deallocate.

## Return Values

None.

## Description

This function takes a data cache that has been locked with the `DC_LockdownRange` function, preventing it from being deleted, and releases this cache so it can be deleted when caches are replaced.

This function releases, in order, a num number of lockdown blocks from the region that was last locked with the `DC_LockdownRange` function.

There are a maximum of three configurable lockdown blocks, so the maximum number of lockdown blocks that can be designated with num is also three.

## Internal Operation

Operates registers 7 and 9 of the system control coprocessor.

## See Also

`DC_LockdownRange,DC_UnlockdownAll`

## Revision History

2005/01/21 Initial version.

CONFIDENTIAL