K60P100M100SF2RM Datasheet, PDF (1679/1809 Pages) Freescale Semiconductor, Inc – K60 Sub-Family Reference Manual

Chapter 53 Integrated interchip sound (I2S)
The I²S supports both normal and network modes, and these can be selected
independently of whether the transmitter and receiver are synchronous or asynchronous.
Typically, these protocols are used in a periodic manner, where data transfers at regular
intervals, such as at the sampling rate of an external codec. Both modes use the concept
of a frame. The beginning of the frame is marked with a frame sync when programmed
with continuous clock. The RCCR[DC] or TCCR[DC] bits determine the length of the
frame, depending on whether data is being transmitted or received.
The number of words transferred per frame depends on the mode of the I²S. In normal
mode, one data word is transferred per frame. In network mode, the frame divides into
two to 32 time slots. In each time slot, one data word is optionally transferred.
Apart from the above basic modes of operation, I²S supports the following modes which
require some specific programming.
• I²S mode
• AC97 mode
• AC97 fixed mode
• AC97 variable mode
In non-I²S slave modes (external frame sync), the I²S's programmed word length setting
should be equal to the word length setting of the master. In I²S slave mode, the I²S's
programmed word length setting can be lesser than or equal to the word length setting of
the I²S master (external codec).
In slave modes, the I²S's programmed frame length setting (TCCR[DC] or RCCR[DC]
bits) can be lesser than or equal to the frame length setting of the master (external codec).
See Detailed operating mode descriptions for more details on the above modes.
53.2 I²S signal descriptions
Signal
SRCK
Table 53-2. I²S signal descriptions
Description
Serial receive clock. SRCK can be used as an input or output.
• In asynchronous mode the receiver uses this clock signal and it is
always continuous.
• In synchronous mode, the STCK port is used instead for clocking in
data.
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K60 Sub-Family Reference Manual, Rev. 6, Nov 2011
Freescale Semiconductor, Inc.
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