Rainbow Electronics APR6008 - Manual (Page 7)

Voice Recording & Playback Device Page 7
Revision 2.1
tion as closely as possible:
EXTCLK freq = (N) * (128) * (selected sampling frequency)
Example:
Suppose that 8.0 KHz sampling is desired. Assume that
the frequency of the signal present on EXTCLK = 8MHz.
Rounding up, N = 8
The Op Code Parameter bit stream, composed of bits
[A9 - A2][A1 - A0], therefore becomes binary
[00001000][10].
The STOP Command causes the device to stop the current
operation.
The STOP_PWDN command causes the device to stop the
current command and enter power down mode. During power
down the device consumes significantly less power. The
PWRUP command must be used to force the device into
power up mode before any commands can be executed.
The SET_REC command instructs the device to begin
recording at the sector address specified. The device will
continue to record until the end of the current sector is
reached. If no forthcoming command has been received
when the end of the sector is reached the device will loop
back to the beginning of the same sector and overwrite the
previously recorded material. If the next command is another
SET_REC or REC command the device will execute the com-
mand immediately following the end of the current sector so
that no audio information is lost. For more information see the
section entitled
Recording Audio Data .
The REC command instructs the device to begin recording in
the current sector. If no new command is received before the
device reaches the end of the sector the device will automati-
cally increment to the next sequential sector and continue
recording. The device will continue to record in this manner
until the memory is exhausted or a
STOP or STOP_PWDN
command is received. For more information see the section
entitled
Recording Audio Data .
The DIG_ERASE command erases all data contained in the
sector specified. Erase should not be done before recording
voice signals into a sector. Erase must be done before storing
digital data in a sector.
The DIG_WRITE command stores 3K bits of digital data in
the specified sector. All 3K bits must be written, no partial
usage of the sector is possible. The memory acts as a FIFO,
the first data bit shifted in will be the first data bit shifted out. A
sector must be erased using the
DIG _ ERASE command
BEFORE data can be written to the sector. For more informa-
tion on storing digital data, see the section entitled
Writing
Digital Data .
The DIG_READ command instructs the device to retrieve
digital data that was previously written to the specified sector.
The first bit shifted out is the first bit that was written. The last
bit shifted out is the last bit that was written. For more infor-
mation on reading digital data see the section entitled
Read-
ing Digital Data.
The SET_PLAY command instructs the device to begin play-
back at the specified sector. If no forthcoming command is
received, or EOD bit encountered, before the end of the sec-
tor is reached the device will loop back to the beginning of the
same sector and continue playback with no noticeable gap in
the audio output. If the next command is another
SET_PLAY
or PLAY command the device will execute the command
immediately following the end of the current sector so that no
gap in playback is present. For more information see the sec-
tion entitled
Playing Back Audio Data.
The PLAY command instructs the device to begin playback at
the current sector. If no forthcoming command is received, or
EOD bit encountered, before the device reaches the end of
the sector the device will automatically increment to the next
sequential sector and continue playing. The device will con-
tinue to play in this manner until the memory is exhausted or
a
STOP or STOP_PWDN command is received. For more
information see the section entitled Playing Back Audio Data.
N
8000000
128 8000
( )
-------------------------- 7.8125 = =
APR6008