SI5347-EVB Datasheet, PDF (19/21 Pages) Silicon Laboratories – Powered from USB port or external

Si5347-EVB
11. Writing a New Frequency Plan or Device Configuration to Non-Volatile
Memory (OTP)
Note: Writing to the device non-volatile memory (OTP is NOT the same as writing a configuration into the Si5347 using Clock-
BuilderPRo on the Si5347 EVB. Writing a configuration into the EVB from ClockBuilderPro is done using Si5347 RAM
space and can be done virtually unlimited numbers of times. Writing to OTP is limited as described below.
Refer to the Si534x/8x Family Reference Manuals and device data sheets for information on how to write a
configuration to the EVB DUT’s non-volatile memory (OTP). The OTP can be programmed a maximum of two
times only. Care must be taken to ensure the configuration desired is valid when choosing to write to OTP.
12. Serial Device Communications
12.1. On-Board SPI Support
The MCU on-board the Si5347-EVB communicates with the Si5347 device through a 4-wire SPI (Serial Peripheral
Interface) link. The MCU is the SPI master and the Si5347 device is the SPI slave. The Si5347 device can also
support a 2-wire I2C serial interface, although the Si5347-EVB does NOT support the I2C mode of operation. SPI
mode was chosen for the EVB because of the relatively higher speed transfers supported by SPI vs. I2C.
12.2. External I²C Support
I²C can be supported if driven from an external I²C controller. The serial interface signals between the MCU and
Si5347 pass through shunts loaded on header J36. These jumper shunts must be installed in J36 for normal EVB
operation using SPI with CBPro. If testing of I²C operation via external controller is desired, the shunts in J36 can
be removed thereby isolating the on-board MCU from the Si5347 device. The shunt at J4 (I2C_SEL) must also be
removed to select I²C as Si5347 interface type. An external I²C controller connected to the Si5347 side of J36 can
then communicate to the Si5347 device. For more information on I²C signal protocol, refer to the Si5347 data
sheet.
Figure 28 illustrates the J36 header schematic. J36 even numbered pins (2, 4, 6, etc.) connect to the Si5347
device, and the odd numbered pins (1, 3, 5, etc.) connect to the MCU. Once the jumper shunts have been removed
from J36 and J4, I²C operation should use J36 pin 4 (DUT_SDA_SDIO) as the I²C SDA and J36 pin 8
(DUT_SCLK) as the I²C SCLK. Note that the external I²C controller will need to supply its own I²C signal pull-up
resistors.
Figure 28. Serial Communications Header J36
Rev. 1.1
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