BU94605AKV Datasheet, PDF (42/84 Pages) Rohm – AAC/WMA/MP3 +SD Memory Card +CD-ROM+MP3 Record

BU94605AKV BU94607AKV BU94702AKV BU94705AKV
Datasheet
19.3 Valid data to be encoded
When LRCK is switched from Rch to Lch and all of the following conditions are met, input data is written to the internal
buffer as valid data and encoded to MP3.
[1] The command to enable the encode function turns ON.
[2] BFULLO output terminal is set to L. (The internal buffer is not FULL.)
[3] INREQI input terminal is set to H. (The microcomputer tells that this data is valid.)
When the internal buffer becomes FULL and cannot receive the data, BFULLO terminal output H. Then, data writing to
the internal buffer will stop.
When the internal buffer generates space after processing data and INREQI input terminal is set to L, BFULLO output
terminal is set to L.
Valid data
INREQI
Input data
BFULLO
Internal buffer
FULL
Internal buffer
Internal encoding flag
Start of encode
Figure 36. Valid data to be encoded
End of encode for buffer
19.4 Data comparison connection function
When you assume the comparison connection operation to be effective, the data newly input as the last 3 samples of
the valid data input before the comparison connection operation is set is compared.
LSI restarts the input from the following data to an internal buffer when 3 consecutive samples are corresponding
everything.
As a result, it becomes consecutive data before and after doing connected operation.
When you assume the comparison connection operation to be invalid, encode can be restarted by connecting it directly
by controlling the INREQI input.
19.5 Encode speed
The data writing speed to the memory depends on the state of the fragmentation and the usage condition in the
memory, response time from the memory.
Therefore, the encode speed that BFULLO doesn't become H for all media cannot be guaranteed.
BFULLO both becomes H while recording MP3 and WAV, and the memory that cannot be in real time recorded exists.
www.rohm.com
© 2012 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
42/80
TSZ02201-0V2V0E600090-1-2
2012.12.10 Rev.002