HARDWARE CONNECTIONS FOR THE DEM-DAI1717
Hardware configuration of the
Digital Audio Source
Figure 11 shows the “schematic” drawing of the DEM- DAI1717 evaluation board. There are a total of four connec- tors that must be used for the PCM1717 to reproduce digital audio data. Figure 12 details the parts location and orienta- tion for the DEM-DAI1717 evaluation board. The PCB layer design for the traces and ground planes used in the DEM-DAI1717 system board are shown in Figure 13.
Digital Audio Input Data
The source of digital audio data is connected via the coax connector labeled as “CN3” or “COAX.” This port is used if the SPDIF digital audio data comes from a RCA connec- tor.
SPDIF data can also be provided to the
Power Connections
A 5 pin connector labeled CN1 is used to connect power to the
The power connections +V | and |
S | S |
the active filter
Analog or Audio Connections
The analog outputs of the PCM1717 are brought out directly through RCA jacks CN6 and CN7 for the left and right channel respectively. These outputs are referred to 1/2 of the VCC voltage, i.e. the output swings symmetrically about 2.5V for a 5V supply.
SOFTWARE DESCRIPTION
The PCM1717 demo software is used to control the internal register settings of the PCM1717 through a set of four windows. The main menu is brought up by clicking on the “D17CTRMK” icon in the applications folder.
MAIN MENU
Figure 14 shows the main menu that is brought up when the “D17CTRMK” icon is selected. This menu has three areas of interest. The “Execute” option allows the user to either reset the PCM1717 to its default power-on state using the Reset command, or allows the user to exit from the PCM1717
software. The execute menu can be opened by either click- ing on the “Execute” or by using the
The bottom of the PCM1717 Main or Control Menu con- tains the Hexadecimal value of the current contents of the PCM1717 four control or Mode Registers. For a more detailed description of these registers consult the product data sheet for the PCM1717E audio
A Pass/Hold selection is available for all three of these control menus. When the Menu is in the Pass mode then commands are sent to the PCM1717 as various selection or options are selected immediately. When the Menu is in the Hold mode the changes are held in the software for the
ATTENUATE MENU
The PCM1717 allows the user to command 255 steps of noiseless attenuation into each channel. The left and right channels can either be controlled together, i.e. equal attenu- ation of both channels, or independent control over each channel. Figure 15 shows the attenuation menu.
To change the attenuation or volume of a channel use the mouse pointer over the bar in the attenuation level menu for the desired channel, press and hold the left button and drag the bar to the desired level. Pressing the Hold selection in the Control Data section of the Attenuation Control Menu will change the Hold section to Pass, and the necessary register settings for the desired attenuation level will be passed to the PCM1717. The level or volume will change. (Note that if the Left and Right channels have been chosen to be equal from the Format Control menu, then only the Left channel Attenu- ation Level will be selectable.)
FORMAT CONTROL MENU
This menu allows the user to program the data input format, resolution,
FORMAT
This menu allows the PCM1717 to be programmed for either the standard or I2S format for incoming data to the DAC. The standard format is used when the incoming data is MSB aligned to the
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