BCM89071A1CUBXGT Datasheet, PDF (62/69 Pages) Cypress Semiconductor – Single-Chip Automotive Grade Bluetooth Transceiver and Baseband Processor

BCM89071 Data Sheet
I²S Interface
I²S Interface
The BCM89071 supports two independent I²S digital audio ports. The I²S interface supports both master and
slave modes. The I²S signals are:
• I²S clock: I²S SCK
• I²S Word Select: I²S WS
• I²S Data Out: I²S SDO
• I²S Data In: I²S SDI
I²S SCK and I²S WS become outputs in master mode and inputs in slave mode, while I²S SDO always stays
as an output. The channel word length is 16 bits and the data is justified so that the MSB of the left-channel data
is aligned with the MSB of the I²S bus, per the I²S specification. The MSB of each data word is transmitted one
bit clock cycle after the I²S WS transition, synchronous with the falling edge of bit clock. Left-channel data is
transmitted when I²S WS is low, and right-channel data is transmitted when I²S WS is high. Data bits sent by
the BCM89071 are synchronized with the falling edge of I2S_SCK and should be sampled by the receiver on
the rising edge of I2S_SCK.
The clock rate in master mode is either of the following:
48 kHz x 32 bits per frame = 1.536 MHz
48 kHz x 50 bits per frame = 2.400 MHz
The master clock is generated from the input reference clock using a N/M clock divider.
In the slave mode, any clock rate is supported to a maximum of 3.072 MHz.
Broadcom^®
April 16, 2015 • 89071-DS106-R
Baseband Transceiver and Baseband Processor
Page 61