USBB13AP77016-XXX-B06 NEC Electronics, USBB13AP77016-XXX-B06 Datasheet - Page 30

• Manufacturer Part Number: USBB13AP77016-XXX-B06
• Description: DSP middleware(AMR voice CODEC)
• Manufacturer: NEC Electronics

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[Notes on simulator]
(3) I/O buffer
The library of the µ SAP77016-B06 reads a memory space other than an allocated area for faster pointer
processing. Therefore, the simulator may issue a warning, depending on the status of memory allocation.
This is an area that is used to input/output speech data and bit stream data. The user can use the I/O buffer
used by the encoder/decoder after encoding/decoding one frame.
encoding/decoding processing, normal operation of the µ SAP77016-B06 is not guaranteed.
• • • • I/O buffer necessary for encoder
• • • • I/O buffer necessary for decoder
Remark
Example:
Example:
amr_Static_enc_x
amr_Static_enc_y
amr_Static_dec_x
amr_Static_dec_y
lib_Scratch_x
lib_Scratch_y
Area Name
Generally, the I/O buffer of speech data is configured as a double buffer when
compression/decompression is executed in real time. In this case, a 320-word data memory is
required in the Y memory space as an I/O buffer used by the encoder/decoder, and another 320-
word data memory is required in either the X or Y memory space as an I/O buffer used for serial
I/O.
Output buffer of bit stream data:
Input buffer of speech data:
Input buffer of bit stream data:
Output buffer of speech data:
I_O_BUFFER_X
bitstream_out:
I_O_BUFFER_Y
speech_in:
I_O_BUFFER_X
bitstream_in:
I_O_BUFFER_Y
speech_out:
Memory space other than this area is not accessed.
Memory space other than this area is not accessed.
Memory space other than this area is not accessed.
Memory space other than this area is not accessed.
Memory in a range from this area to +5 words is accessed.
Memory in a range from the beginning of this area to –1 word is accessed.
CHAPTER 2 LIBRARY SPECIFICATIONS
Table 2-7. Memory Access Range
User’s Manual U15165EJ3V0UM
XRAMSEG
DS
YRAMSEG
DS
XRAMSEG
DS
YRAMSEG
DS
16 words in X memory space
160 words in Y memory space
16
160
16 words in X memory space
160 words in Y memory space
16
160
Description
If the buffer is manipulated during