Introduction - Analog Devices VisualDSP++ 5.0 Service Manual

Introduction

Introduction
The initial goal of the external bus interface unit (EBIU) module is to
enable the power management module to adjust the SDRAM or DDR
controller (SDC) in accordance with changes made to the system clock
( ) frequency. Calls to both
SCLK
adi_pwr_SetMaxFreqForVolt
quency selected, provided the EBIU module has been initialized.
information, see "Power Management Module" on page 3-1.
Using the module is straightforward. The
called to set up the relevant values listed in the appropriate data sheet for
the external memory device. Thereafter, the refresh rate for SDRAM or
DDR is adjusted automatically each time the power management module
changes . The asynchronous memory controller is not automatically
SCLK
adjusted but can be explicitly reconfigured via a call to
The "Using the EBIU Module"
of how to work with the EBIU module. Sample code is also included.
The EBIU module uses an unambiguous naming convention to safeguard
against conflicts with other software libraries provided by Analog Devices
or other companies. All enumeration values and
the
ADI_EBIU_
equivalent,
adi_ebiu_
Two versions of the library are available for each processor, corresponding
to the debug and release configurations in VisualDSP++. In addition to
the usual defaults for the debug configuration, the API functions perform
checks on the passed arguments and report appropriate error codes, as
required. In the release version of the library, most functions return one of
two result codes:
ADI_EBIU_RESULT_NOT_INITIALIZED
initialized prior to the function call.
4-2
adi_pwr_SetFreq
adjust the SDC settings to the
section provides a step-by-step description
prefix, and functions and global variables use the lowercase
.
ADI_EBIU_RESULT_SUCCESS
VisualDSP++ 5.0 Device Drivers and System
and
adi_ebiu_Init
typedef statements
on successful completion, or
when the EBIU module has not been
Services Manual for Blackfin Processors
fre-
SCLK
For more
function is
adi_ebiu_Control
use
.