User guide

APR6008
Page 8 Voice Recording & Playback Device
Revision 2.1
Receiving Device Information
The device communicates data to the user by shifting out
data on the DO pin. The device will shift out data accordin
g to
the timin
g parameters given in figure 7. The device can shift
out three different types of data streams: Device status, Sili-
con ID, and user stored data. Device status and silicon ID are
described in the next two sections. Retrieval of user data is
described in the
Reading Digital Data
section.
Figure 7 Data Out Timing
Current Device Status (CDS)
As described in the previous section, three different types of
data streams are shifted out on the DO pin as data is shifted
in on the DI pin. One of these steams is the current device
status. The CDS will be shifted out unless the previous com-
mand is SID command. Fi
gure 8 shows the format of the
CDS bit stream. The first bit shifted out, D0, is the Overflow
fla
g. The Overflow flag is set to a binary 1 if an attempt was
made to record be
yond the available memory. The Overflow
fla
g is set to a 0 if an overflow has not occurred. This flag is
cleared after it has been read. The D1 bit is the End of Data
fla
g. The EOD flag is set when the device stops playing, or
fast forwardin
g as a result of an EOD bit in memory. The EOD
fla
g is cleared after it has been read. The D2 bit is the Illegal
Address fla
g. The Illegal Address flag is set whenever an ille-
gal address is sent to the device. The D3 bit is the Lbat flag.
This fla
g is set when the device senses a supply voltage
below specification. The D4 bit is not used and should be
i
gnored. The last fifteen bits represent the address of the cur-
rent or last active sector.
Figure 8Format for CDS Bit Stream
Op4
Op3
Op2 Op1
A1
A2
A0
/CS
SCLK
DI
D0
D1 D2 D18 D17 D19 D16
D3
~
~
~
~
~
~
DO
T
fcsDO
T
fSCLK
T
hzD0
D15
~
~
A3
Lbat
OVF
EOD
Ille
gal Address
D0 D1 D3 D4 D5 D6 D7 D8 D9 D10 D11 D12 D13 D14 D2
~
~
D19
}
First bit shifted outLast bit shifted out
Sector Address
Sector
Addre
ss MSB
Sector Add
res s
LSB