Dma Service; Semaphore Service - Analog Devices VisualDSP++ 5.0 Service Manual

System Service Requirements

DMA Service

The DMA manager is used by the file system service to transfer data
between the application and the physical media, where appropriate, as
determined by the nature of each PID in the application. The use of DMA
and the channels affected are detailed in the appropriate PID device driver
documents. The value given to the
incremented by the number of DMA channels required by each PID.
The DMA requirements for each physical device driver are detailed in the
documentation for that appropriate driver. For example, the ATAPI driver
requires the DMA manager to be initialized for two DMA channels; the
SD PID, one channel; and the USB host driver, no DMA channels.

Semaphore Service

The file system service requires a number of semaphores for its operation.
The semaphores are used to maintain atomic access to file system and
physical interface drivers and for notification of completion of data trans-
fers. For each instance of an FSD or PID, at least two semaphores are
required. (See the appropriate drive documentation for precise details.)
Please note that if the application makes simultaneous use of two or more
types of media that require the use of the same file system driver, then two
semaphores are required for each instantiation of the appropriate FSD
driver.
The number of semaphores required also varies in proportion to the num-
ber of files that are opened at one time, as the use of the file cache requires
one semaphore per open file.
The value given to the
by the number of semaphores required for the required FSS configuration.
12-10
ADI_SSL_DMA_NUM_CHANNELS
ADI_SSL_SEM_NUM_SEMAPHORES
VisualDSP++ 5.0 Device Drivers and System
Services Manual for Blackfin Processors
must be
must be incremented