Serial Host Interface
SHI Programming Considerations
MOTOROLA
DSP56367
9-29
number of bytes in an I
2
C frame so that they fit in a complete number of words. Remember
that for this purpose, the slave device address byte does not count as part of the data.
In a transmit session, only the transmit path is enabled and the IOSR-to-HRX FIFO transfers
are inhibited. When the HTX transfers its valid data word to the IOSR, the HTDE status bit is
set and the DSP may write a new data word to HTX with either DSP instructions or DMA
transfers. If both IOSR and HTX are empty, the SHI suspends the serial clock until new data
is written into HTX (when the SHI proceeds with the transmit session) or HIDLE is set (the
SHI reactivates the clock to generate the stop event and terminate the transmit session).
9.7.5
SHI OPERATION DURING DSP STOP
The SHI operation cannot continue when the DSP is in the stop state, because no DSP clocks
are active. While the DSP is in the stop state, the SHI remains in the individual reset state.
While in the individual reset state the following is true:
•
If the SHI was operating in the I
2
C mode, the SHI signals are disabled (high
impedance state).
•
If the SHI was operating in the SPI mode, the SHI signals are not affected.
•
The HCSR status bits and the transmit/receive paths are reset to the same state
produced by hardware reset or software reset.
•
The HCSR and HCKR control bits are not affected.
Note:
It is recommended that the SHI be disabled before entering the stop state.
Summary of Contents for DSP56367
Page 16: ...xvi MOTOROLA CONTENTS Paragraph Number Title Page Number ...
Page 22: ...xxii MOTOROLA List of Figures Figure Number Title Page Number ...
Page 26: ...xxvi MOTOROLA List of Tables Table Number Title Page Number ...
Page 148: ...4 6 DSP56367 MOTOROLA Design Considerations PLL Performance Issues ...
Page 248: ...9 30 DSP56367 MOTOROLA Serial Host Interface SHI Programming Considerations ...
Page 306: ...10 58 DSP56367 MOTOROLA Enhanced Serial Audio Interface ESAI ESAI Initialization Examples ...
Page 389: ...Bootstrap ROM Contents MOTOROLA DSP56367 A 15 end ...
Page 390: ...A 16 DSP56367 MOTOROLA Bootstrap ROM Contents ...
Page 432: ...C 8 DSP56367 MOTOROLA JTAG BSDL ...
Page 484: ...D 52 DSP56367 MOTOROLA Programmer s Reference ...
Page 490: ...E 6 DSP56367 MOTOROLA Power Consumption Benchmark ...
Page 516: ...F 26 DSP56367 MOTOROLA IBIS Model ...
Page 522: ...Index 6 MOTOROLA Index ...
Page 523: ......