USBB17AP77016-XXX-B11 NEC Electronics, USBB17AP77016-XXX-B11 Datasheet - Page 27

• Manufacturer Part Number: USBB17AP77016-XXX-B11
• Description: DSP middleware(WMA (Windows Media Audio)decoder)
• Manufacturer: NEC Electronics

2.5.1
Note, however, that because the scratch area is used once more when the middleware starts operating again, if the
user has set information in this area, the set information may be changed at this time.
to make align or at specifications. The size of the area differs depending on the supported bit rate. For details, refer to
Table 2-4 Memory Size Required for Each Bit Rate. Be sure to make a PUBLIC declaration for defined symbols.
public
public
;When all bit rates are supported
#define WMAD_MAX_SCRATCH_X_SIZE 1572
#define WMAD_MAX_SCRATCH_Y_SIZE 299
_ _ WMAD_LIB_SCRATCH_X
wmad_lib_Scratch_x:
_ _ WMAD_LIB_SCRATCH_Y
wmad_lib_Scratch_ y :
end
This is a memory area that can be freed up and used by the user when the µ SAP77016-B11 is not operating.
Secure the scratch area under the label names wmad_lib_Scratch_x and wmad_lib_Scratch_y. It is not necessary
Bit Rate
16,000
16,000
16,000
16,000
12,000
12,000
10,000
10,000
8,000
8,000
6,000
5,000
[bps]
128
Scratch area
Frequency [Hz]
Sampling
wmad_lib_Scratch_x
wmad_lib_Scratch_y
22,050
22,050
16,000
16,000
16,000
16,000
11,025
11,025
8,000
8,000
8,000
8,000
8,000
Table 2-4. Memory Size Required for Each Bit Rate (2/2)
Number of
Channels
Figure 2-3. Example of Securing Scratch Area
1
1
2
1
1
2
1
1
1
1
1
1
1
XRAMSEG
DS
YRAMSEG
DS
CHAPTER 2 LIBRARY SPECIFICATIONS
WMA CODEC
WMAD_MAX_SCRATCH_X_SIZE;
WMAD_MAX_SCRATCH_Y_SIZE;
Version
2, 7, 8
2, 7, 8
2, 7, 8
2, 7, 8
2, 7, 8
2, 7, 8
2, 7, 8
2, 7, 8
2, 7, 8
2, 7, 8
2, 7, 8
User’s Manual U15683EJ1V0UM
2, 7
8
static_x1
972
972
972
972
972
972
972
972
972
972
972
972
972
X Memory Size [Words]
static_x2
2,048
2,048
1,024
1,024
2,048
1,024
1,024
1,024
1,024
1,024
1,024
1,024
0
scratch
1,572
1,572
1,572
1,572
1,572
1,572
1,572
1,572
1,572
1,572
1,572
1,572
1,572
static_y1
8,192
8,192
8,192
8,192
8,192
8,192
8,192
8,192
8,192
8,192
8,192
8,192
8,192
Y Memory Size [Words]
static_y2
1,024
1,024
1,024
1,024
512
512
512
512
512
512
512
512
512
scratch
299
299
299
299
299
299
299
299
299
299
299
299
0
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