PEB20571 Datasheet, PDF (129/308 Pages) Infineon Technologies AG – DSP Embedded Line and Port Interface Controller

PEB 20570
PEB 20571
Functional Description
A-/µ-law to Linear Conversion
The conversion is done via a 512 x 16 ROM table. The low 256 bytes translate the A-law
value into linear, while the high 256 words translate the µ-law to linear.
The DSP issues a read cycle, in which the 8 MSBs of the 16-bit address represent the
ROM table address, and the 8 LSBs are the actual value which is to be converted. The
converted linear value is the contents read from the ROM. Note that no wait states are
required for this direction of conversion.
A-law values in the ROM are stored in the 13 MSBs. The 3 LSBs are always '0'. The µ-
law values in the ROM are stored in the 14 MSBs. The 2 LSBs are always '0'.
Linear to A-/µ-law Conversion
The conversion is done by dedicated hardware. The DSP programs the control register
to perform either A-law or µ-law conversion. The linear value is written into the Input
register (AMIR), and the A-law or µ-law value is read from the Output register (AMOR).
Note that this is only possible one cycle later.
Data Sheet
112
2003-07-31