Freescale Semiconductor DSP56366 - Manual (Page 34)

Peripheral Overview
DSP56366 24-Bit Digital Signal Processor User Manual, Rev. 4
1-10 Freescale Semiconductor
1.5.4 Enhanced Serial Audio Interface (ESAI)
The ESAI provides a full-duplex serial port for serial communication with a variety of serial devices
including one or more industry-standard codecs, other DSPs, microprocessors, and peripherals that
implement the Freescale SPI serial protocol. The ESAI consists of independent transmitter and receiver
sections, each with its own clock generator. It is a superset of the DSP56300 family ESSI peripheral and
of the DSP56000 family SAI peripheral. For more information on the ESAI, refer to
Section 8, "Enhanced
Serial AUDIO Interface (ESAI)" .
1.5.5 Enhanced Serial Audio Interface 1 (ESAI_1)
The ESAI_1 is a second ESAI interface with just 6 dedicated pins instead of the 12 pins of the full ESAI.
Four data pins are shared with the ESAI, while the two high frequency clock pins are not available. Other
than the available pins, ESAI_1 is functionally identical to ESAI. For more information on the ESAI_1,
refer to
Section 9, "Enhanced Serial Audio Interface 1 (ESAI_1)" .
1.5.6 Serial Host Interface (SHI)
The SHI is a serial input/output interface providing a path for communication and program/coefficient data
transfers between the DSP and an external host processor. The SHI can also communicate with other serial
peripheral devices. The SHI can interface directly to either of two well-known and widely used
synchronous serial buses: the Freescale serial peripheral interface (SPI) bus and the Philips
inter-integrated-circuit control (I
2
C) bus. The SHI supports either the SPI or I
2
C bus protocol, as required,
from a slave or a single-master device. To minimize DSP overhead, the SHI supports single-, double-, and
triple-byte data transfers. The SHI has a 10-word receive FIFO that permits receiving up to 30 bytes before
generating a receive interrupt, reducing the overhead for data reception. For more information on the SHI,
refer to
Section 7, "Serial Host Interface" .
1.5.7 Digital Audio Transmitter (DAX)
The DAX is a serial audio interface module that outputs digital audio data in the AES/EBU, CP-340 and
IEC958 formats. For more information on the DAX, refer to
Section 10, "Digital Audio Transmitter" .