User guide

CY3280-MBR3 Evaluation Kit User Guide, Doc. #: 001-89905 Rev. *B 76

Advanced Topics

6. The MBR3 device is in a deep-sleep state until a CapSense or I

C activity occurs. When receiv-

ing an I

C command while in deep sleep, MBR3 will NACK the request and begin to wake from

sleep. This I

C approach is in lieu of I

C clock stretching, which may corrupt non-stretching com-

pliant devices on the bus. An I

C command sent from BCP may not be acknowledged. Therefore,

resend the I

C command until the MBR3 device wakes and acknowledges. Two dummy write

operations to the MBR3 device are sufficient before sending the 128-byte configuration. To send

a dummy write, edit each write command in the IIC file with the prefix “w 37 0 p w 37 0 p”.

7. From the BCP, transfer the 128-byte configuration data to the MBR3 device; to do this, place the

cursor on the command to be sent to the MBR3 device and click the Send button on the GUI or

press the Enter key on your keyboard. The log shows if the transaction is a success or failure. A

“+” after each byte indicates that the transaction is a success and a “–” indicates that it is a failure

(see Figure 6-4).

8. Send both I

C commands in the IIC file to see the configuration in effect on the CY3280-MBR3

kit.

9. Press the reset switch, SW2, on the kit. The configuration specified by 128 bytes in the first com-

mand will take effect.

Note: See LED Toggle on page 52 for more details and expected output of the LED Toggle con-

figuration.

Figure 6-4. Writing to I

C Slave in BCP

10.Read five bytes of data from the register offset address 0x00 of the MBR3 device. The log shows

if the transaction is a success or a failure.