VS1011E Datasheet, PDF (45/49 Pages) List of Unclassifed Manufacturers – MPEG AUDIO CODEC

VLSI
Solution ^y
VS1011e
VS1011E
10. VS1011E REGISTERS
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.
10.10 System Vector Functions
The System Vector Functions are pointers to some functions that the user may call to help implementing
his own applications.
10.10.1 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.
10.10.2 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.
10.10.3 DataBytes(), 0x6
VS DSP C prototype:
u int16 DataBytes(void);
If the user has taken over the normal operation of the system by switching the pointer in UserCodec
to point to his own code, he may read data from the Data Interface through this and the following two
functions.
This function returns the number of data bytes that can be read.
Version 1.04, 2007-10-08
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