ISD25120P View Datasheet(PDF) - Information Storage Devices

Part Name

Description

Manufacturer

ISD25120P

Single-Chip Voice Record/Playback Devices 32-*, 40-*, 48-*, 64-*, 60-, 75-, 90-, and 120-Second Durations

Information Storage Devices 

ISD2500 Series

Product Data Sheets

ISD1000A COMPATIBILITY

The ISD2500 Series of devices is designed to pro-

vide upward compatibility with the ISD1000A

family. When designing with the ISD2500 Series,

the following differences should be noted.

Addressing

The ISD2560/75/90/120 devices have 480K stor-

age cells designed to provide 60 seconds of

storage at a sampling rate of 8.0 KHz. This is

approximately four times the storage of the

ISD1000A family. To enable the same addressing

resolution, two additional address pins have been

added. The address space of each device is divis-

ible into 300 increments with valid addressing from

00 to 13F Hex. Some higher addresses are

-1 mapped into the Operational Modes. All other

addresses are invalid.

The ISD2532/40/48/64 devices have 256K storage

cells designed to provide 32 seconds of storage at

a sampling rate of 8.0 KHz. This is twice the

amount of storage of the ISD1000A family. To

enable the same addressing resolution, one addi-

tional address pin has been added. The address

space of each device is divisable into 320 incre-

ments with valid addressing from 00 to 13F Hex.

Overflow

The ISD1000A Series combined two functions on

the EOM pin: end-of-message indication and over-

flow. The ISD2500 separates these two functions.

Pin 25 (PDIP package) remains as EOM, but out-

puts only the EOM signal indication. Pin 22 (PDIP

package) becomes OVF and pulses LOW only

when the device reaches its end of memory, or is

“full.” This change allows easy message cueing

and addressability across device boundaries. This

also means that the M2 operational mode found in

the ISD1000A family is not implemented in the

ISD2500 Series.

Push-Button Mode

The ISD2500 Series includes an additional Opera-

tional Mode called Push-Button mode. This

provides an alternative interface to the Record and

Playback functions of the part. The CE and PD

pins become redefined as edge-activated “push-

buttons.” A pulse on CE initiates a cycle, and if

triggered again, pauses the current cycle without

resetting the address pointer (i.e., a Start or Pause

function). PD stops any current cycle and resets

the address pointer to the beginning of the mes-

sage space (i.e., a Stop and Reset function).

Additionally, the EOM pin functions as an active-

HIGH run indicator, and can be used to drive an

LED indicating a Record or Playback operation is

in progress. Devices in the Push-Button mode can-

not be cascaded.

Looping Mode

The ISD2500 Series can loop with a message that

completely fills the memory space.

NOTE

Additional descriptions of ISD2500 device

functionality and application examples are

provided in the ISD Application Notes and

Design Manual in this book.

1–88

* Advance information: ISD2532/40/48/64 devices.

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