User guide

ManualsBrandsRainbow Electronics ManualsAcousticsAPR6008

Voice Recording & Playback Device Page 3

Revision 2.1

Memory Organization

The APR6008 memory array is organized to allow the great-

est flexibilit

y in message management and digital storage.

The smallest addressable memor

y unit is called a “sector”.

The APR6008 contains 640 sectors.

Figure 3 Memory Map.

Sectors 0 through 639 can be used for analog storage. Du -

ring

audio recording one memory cell is used per sample

clock c

ycle. When recording is stopped an end of data (EOD)

bit is programed into the memory. This prevents playback of

silence when partial sectors are used. Unused memor

y that

exists between the EOD bit and the end of the sector can not

be used.

Sectors 0 throu

gh 9 are tested and guaranteed for digital

stora

ge. Other sectors, with the exception of sector 639, can

store data but have not been tested, and are thus not

guaran-

teed to provide 100%

good bits. This can be managed with

error correction or forward check-before-store methods.

Once a write c

ycle is initiated all previously written data in the

chosen sector is lost.

Mixin

g audio signals and digital data within the same sector is

not possible.

Note: There are a total of 15bits reserved for addressing. The

APR6008 only

requires 10 bits. The additional 5 bits are used

for larger devices within the APR6008 family.

SPI Interface

All memory management is handled by an external host pro-

cessor. The host processor communicates with the APR6008

throu

gh a simple Serial Peripheral Interface (SPI) Port. The

SPI port can run on as little as three wires or as man

y as

seven dependin

g on the amount of control necessary. This

section will describe how to mana

ge memory using the

APR6008 SPI Port and associated OpCode commands.

This topic is broken down into the followin

g sections:

•Sendin

g Commands to the Device

•OpCode Command Description

•Receivin

g Device Information

•Current Device Status

(CDS)

•Reading the Silicon Identification (SID)

•Writin

g Digital Data

•Readin

g Digital Data

•Recordin

g Audio Data

•Pla

ying Back Audio Data

•Handshakin

g Signals

Sending Commands to the Device

This section describes the process of sendin

g OpCodes to

the APR6008 All Opcodes are sent in the same wa

y with the

exception of the

DIG_WRITE

and

DIG_READ

commands

The

DIG_WRITE and DIG_READ

commands

are

described

in the

Writing Digital Data

and

Reading Digital Data

sections

that follow. The minimum SPI confi

guration needed to send

commands uses the DI, /CS, and SCLK pins. The device will

accept inputs on the DI pin whenever the /CS pin is low.

OpCode commands are clocked in on the risin

g edge of the

SPI clock. Fi

gure 4 shows the timing diagram for shifting

OpCode commands into the device. Figure 5 is a description

of the OpCode stream.

You must wait for a command to finish executin

g before send-

g a new command. This is accomplished by monitoring the /

BUSY pin. You can substitute monitorin

g of the busy pin by

inserting a fixed delay between commands. The required

dela

y is specified as

next1

next2

next3

or T

next4

. Figure 6

shows the timin

g diagram for sending consecutive com-

mands. Table 1 describes which

specification to use.

Sector 0

Sector 1

Sector 639

Can Not be Used for Digital Data

SAC Trigger Point

APR6008