CDB6420 Просмотр технического описания (PDF) - Cirrus Logic

Номер в каталоге

Компоненты Описание

Список матч

CDB6420

Full-Duplex Speakerphone Chip

Cirrus Logic 

CDB6420

Figure 8. Reset Options

variables to their default values. A warm reset

saves certain key variables to allow the CS6420 to

adapt to the echo path more quickly.

The function of the reset button in the main win-

dow are controlled by the radio buttons in the group

"When Reset Button is pushed:". The first option

will force the CS6420 into a low power mode by

holding RST low until the button is pushed again

(the text on the button will change to reflect this).

The second option will send the current settings of

the four registers to the CS6420 immediately after

performing the reset. The last option will restore

the default values of the registers to the CS6420,

which is the mode selected when the program is

initially started. Note that this option also changes

the register settings in the main window. Also note

that once this type of reset is invoked, the reset type

will automatically be changed to restore current

register values.

Main Window

Figure 9 shows the main window of the CDB6420

Control Program. The main window is a block di-

agram representation of the internals of the CS6420

with all the registers placed in their appropriate lo-

cations in the signal flow. The right side of the

screen is the Near End (or Acoustic Interface), and

the left side is the Far End (or Network Interface.

See figure 9). The upper path is the Receive Path,

and the lower path is the Transmit Path. The hexa-

decimal values of the registers given the current

settings of the controls is given in the lower left

corner. These values are sent to the CS6420 over

the microcontroller interface.

The Controls

There are 27 controls in the CDB6420 Control Pro-

gram main window. These controls map to the four

registers in the CS6420 whose register values can

be seen in hexadecimal format in the lower left of

the main window. The controls can be easily nav-

igated by using the "Tab" key to traverse the con-

trols from left to right, and "Shift-Tab" to reverse

the direction. Furthermore, the four most common-

ly used controls have hotkeys which will take you

to them: RVol (Ctrl+1), TVol (Ctrl+2), NCC

(Ctrl+3), and ACC (Ctrl+4). These are also acces-

sible from the “Control” menu.

Drop-down Box Hints

Once familiar with the values in the drop-down

boxes, one can easily choose specific values by

typing the first letter of the selection, or using the

up and down arrow keys. Typing the first letter of

the selection can help avoid lots of scrolling and

unnecessary writes to the microcontroller interface.

For example, if RVol is currently selected, its value

can be changed to 30 dB by pressing 3 once and to

3 dB by pressing it again. 0 dB is selected by press-

ing 0, and pressing "m" will select mute. Alterna-

tively, if the value is 0 dB, pressing the down arrow

will set the register to -3 dB, and pressing the up ar-

row will set the value to 3 dB.

As another example, when manipulating the

Acoustic Coefficient Controls (ACC) drop-down

box, the desired setting of the three available selec-

tions ("Normal", "Clear", and "Freeze") can be

chosen with the keys "n", "c", and "f". If using the

arrow keys, going to Freeze from Normal would al-

ways result in a Clear, which may not be desired, so

pressing "f" would be preferable. You can always

use the mouse to select the value.

DS205DB1

45

Share Link: