VS1002D Datasheet, PDF (50/54 Pages) List of Unclassifed Manufacturers – MP3 AUDIO CODEC

VLSI
Solution ^y
VS1002d
VS1002D
10. VS1002D REGISTERS
10.13.9 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 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.
10.14 System Vector Functions
The System Vector Functions are pointers to some functions that the user may call to help implementing
his own applications.
10.14.1 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 only supported way to write to the User Instruction RAM. This is because Instruction RAM
cannot be written when program control is in RAM. Thus, the actual implementation of this function is
in ROM, and here is simply a tag to that routine.
10.14.2 ReadIRam(), 0x4
VS DSP C prototype:
u int32 ReadIRam(register i0 u int16 *addr);
This is the only supported way to read from the User Instruction RAM. This is because Instruction RAM
cannot be read when program control is in RAM. Thus, the actual implementation of this function is in
ROM, and here is simply a tag to that routine.
A1 contains the MSBs and a0 the LSBs of the result.
Version 1.0, 2005-04-27
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