VS1033 Datasheet, PDF (67/70 Pages) List of Unclassifed Manufacturers – MP3/AAC/WMA/MIDI AUDIO CODEC

VLSI
Solution ^y
VS1033a PRELIMINARY
VS1033A
10. VS1033 REGISTERS
10.14.9 UserCodec, 0x0
Normally contains the following VS DSP assembly code:
jr
nop
If the user wants to take control away from the standard decoder, the first instruction should be replaced
with an appropriate j command to user’s own code.
Unless the user is feeding MP3 or WMA data at the same time, the system activates the user program
in less than 1 ms. After this, the user should steal interrupt vectors from the system, and insert user
programs.
10.15 System Vector Functions
The System Vector Functions are pointers to some functions that the user may call to help implementing
his own applications.
10.15.1 WriteIRam(), 0x2
VS DSP C prototype:
void WriteIRam(register i0 u int16 *addr, register a1 u int16 msW, register a0 u int16 lsW);
This is the preferred way to write to the User Instruction RAM.
10.15.2 ReadIRam(), 0x4
VS DSP C prototype:
u int32 ReadIRam(register i0 u int16 *addr);
This is the preferred way to read from the User Instruction RAM.
A1 contains the MSBs and a0 the LSBs of the result.
10.15.3 DataBytes(), 0x6
VS DSP C prototype:
Version 0.6, 2005-01-05
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