![NXP Semiconductors MKL27Z128VFM4 Reference Manual Download Page 805](http://html1.mh-extra.com/html/nxp-semiconductors/mkl27z128vfm4/mkl27z128vfm4_reference-manual_1721847805.webp)
I2Sx_RCR2 field descriptions (continued)
Field
Description
0
Use the normal bit clock source.
1
Swap the bit clock source.
28
BCI
Bit Clock Input
When this field is set and using an internally generated bit clock in either synchronous or asynchronous
mode, the bit clock actually used by the receiver is delayed by the pad output delay (the receiver is
clocked by the pad input as if the clock was externally generated). This has the effect of decreasing the
data input setup time, but increasing the data output valid time.
The slave mode timing from the datasheet should be used for the receiver when this bit is set. In
synchronous mode, this bit allows the receiver to use the slave mode timing from the datasheet, while the
transmitter uses the master mode timing. This field has no effect when configured for an externally
generated bit clock .
0
No effect.
1
Internal logic is clocked as if bit clock was externally generated.
27–26
MSEL
MCLK Select
Selects the audio Master Clock option used to generate an internally generated bit clock. This field has no
effect when configured for an externally generated bit clock.
NOTE: Depending on the device, some Master Clock options might not be available. See the chip-
specific information for the availability and chip-specific meaning of each option.
00
Bus Clock selected.
01
Master Clock (MCLK) 1 option selected.
10
Master Clock (MCLK) 2 option selected.
11
Master Clock (MCLK) 3 option selected.
25
BCP
Bit Clock Polarity
Configures the polarity of the bit clock.
0
Bit Clock is active high with drive outputs on rising edge and sample inputs on falling edge.
1
Bit Clock is active low with drive outputs on falling edge and sample inputs on rising edge.
24
BCD
Bit Clock Direction
Configures the direction of the bit clock.
0
Bit clock is generated externally in Slave mode.
1
Bit clock is generated internally in Master mode.
23–8
Reserved
This field is reserved.
This read-only field is reserved and always has the value 0.
DIV
Bit Clock Divide
Divides down the audio master clock to generate the bit clock when configured for an internal bit clock.
The division value is (DIV + 1) * 2.
Chapter 40 Synchronous Audio Interface (SAI)
KL27 Sub-Family Reference Manual , Rev. 5, 01/2016
Freescale Semiconductor, Inc.
805