53.4.3.1 Supported data alignment formats
The I2S supports three data formats to provide flexibility with handling data. These
formats dictate how data is written to (and read from) the data registers. Therefore, data
can appear in different places in TX0/1 and RX0/1 based on the data format and the
number of bits per word. Independent data formats are supported for both the transmitter
and receiver (that is, the transmitter and receiver can use different data formats).
The supported data formats are:
msb alignment
lsb alignment
Zero-extended (receive data only)
Sign-extended (receive data only)
With msb alignment, the most significant byte is bits 31 through 24 of the data register if
the word length is larger than or equal to 16 bits. If the word length is less than 16 bits
and msb alignment is chosen, the most significant byte is bits 15–8. With lsb alignment,
the least significant byte is bits 7–0. Data alignment is controlled by the TCR[TXBIT0]
bit and the RCR[RXBIT0] bit. See the following table for the bit assignment for all the
data formats supported by the I2S.
Table 53-53. Data alignment
Format
Bit number
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
8-bit lsb aligned
7:0
8-bit msb aligned
7:0
10-bit lsb aligned
9:0
10-bit msb aligned
9:0
12-bit lsb aligned
11:0
12-bit msb aligned
11:0
16-bit lsb aligned
15:0
16-bit msb aligned
15:0
18-bit lsb aligned
17:0
18-bit msb aligned
17:0
20-bit lsb aligned
19:0
20-bit msb aligned
19:0
22-bit lsb aligned
21:0
22-bit msb aligned
21:0
Table continues on the next page...
Chapter 53 Integrated interchip sound (I2S)
K60 Sub-Family Reference Manual, Rev. 6, Nov 2011
Freescale Semiconductor, Inc.
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