ISD-ES501.PDF

02/10/06

Clicking on GO TO BEGINNING simply loads address zero into the ISD5008’s address registers and is

generally used with the IGNORE ADDR setting.

The block to the right of the IGNORE ADDR/USE ADDRESS button shows the status of the chip’s

address during record or playback and indicates the current address after an operation ceases. The OVF

and EOM indicate if the status of the chip if an internal interrupt occurs. Note that during record or

playback the address indication displayed in the white block may lag somewhat behind the actual address

in the chip. During active record and play operations, this readout is for reference only. The address

displayed after a record or play cycle ends will be correct, however.

The section of the display to the top of the screen shows the setup of the two configuration registers. See

the ISD5008 data sheet for more details on these registers. The hex values in the two blocks to the left of

the display are those that may be written to the chip to set up the configuration indicated.

The vertical set of blocks to the lower right of the display show the SPI bits in real time as they are sent to

the chip to perform the desired functions.

The attached PC board layout shows the analog connections to the ISD5001 demo board prototype.

ANA OUT is a differential output and comes out through a stereo jack as indicated. The Speaker output

is a stereo jack used without a ground connection to differentially drive a monaural speaker. AUX IN and

ANA IN are provided together through a stereo jack. This is done so that a standard shielded stereo

cable may be connected between a PC sound board output and this input. This allows the left channel to

drive one of the inputs and the right channel to drive the other. The left and right channels may be wired

differently from system to system so it is left for the user to empirically determine which channel is ANA IN

and which is AUX IN. It’s a nice demo to run stereo audio into the demo unit with the two stereo

channels driving ANA IN and AUX IN. The two channels can be mixed in the SUM 1 mixer and

demonstrated by turning them on and off individually.