AK7735EQ Datasheet, PDF (89/142 Pages) Asahi Kasei Microsystems – Dual DSP with 4chADC + 4chDAC + 4chSRC

[AK7735]
4. Not Acknowledge
The AK7735 cannot receive instructions while the RDY pin (Data Write Ready pin) is at a low level. The
maximum transition time of the RDY pin from low level to high level is 2 × LRCK. It is possible to confirm
in a faster cycle than 2 x LRCK that the RDY pin becomes high by checking the AK7735 internal
condition, which is made by verifying the acknowledgement.
4-1. Generation of “Not Acknowledge”
The AK7735 does not accept command codes until the RDY pin becomes high, when a command is
received to set the RDY pin to a low level. In order to confirm the RDY pin condition, a “Write
Slave-Address assignment” should be sent after the Start condition. If the RDY pin is then at a low level,
“Acknowledgement” is not generated at the succeeding clock (generation of “Not Acknowledged”).
After sending “Not Acknowledged”, the BUS is released and all receiving data are ignored until the next
start condition (behaves as if it received Slave address of other device).
4-2. When Read Slave-address assignment is received without receiving Read command code
Data read in the AK7735 can be made only in the previously documented Read sequence. Data cannot
be read out without receiving a read command code. In the AK7735, a “Not Acknowledged” is generated
when a “Read Slave-address Assignment” without proper receipt of read command is received.
5. Limitation in use of I2C Interface
The AK7735 does not operate in Hs Mode (max: 3.4MHz). The AK7735 supports Fast mode (max:
400kHz) and Fast plus mode (max: 1MHz).
Note
* 72. Do not turn off the power of the AK7735 whenever the power supplies of other devices of the same
system are turned on. Pull-up resistors of SDA and SCL pins should be connected to TVDD or less
voltage. (The diodes against TVDD exist in the SDA and SCL pins.)
016014707-E-00
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2016/12