dsp56366 Freescale Semiconductor, Inc, dsp56366 Datasheet - Page 102

• Manufacturer Part Number: dsp56366
• Description: Dsp56366 24-bit Audio Digital Signal Processor
• Manufacturer: Freescale Semiconductor, Inc

5.5.2
5-6
•
•
sure that the part has completed its HI port programming (e.g., by setting the INIT bit in ICR then
polling it and waiting it to be cleared, then reading the ISR or by writing the TREQ/RREQ together
with the INIT and then polling INIT, ISR, and the HOREQ pin).
Synchronization of Status Bits from Host to DSP—DMA, HF1, HF0, HCP, HTDE, and HRDF
status bits are set or cleared by the host processor side of the interface. These bits are individually
synchronized to the DSP clock. (Refer to the user’s manual for descriptions of these status bits.)
Reading HF0 and HF1 as an Encoded Pair—Care must be exercised when reading status bits
HF0 and HF1 as an encoded pair, (i.e., the four combinations 00, 01, 10, and 11 each have
significance). A very small probability exists that the DSP will read the status bits synchronized
during transition. Therefore, HF0 and HF1 should be read twice and checked for consensus.
DSP Programming Considerations
DSP56366 Technical Data, Rev. 3.1
Freescale Semiconductor