SI5340-EVB Datasheet, PDF (16/19 Pages) Silicon Laboratories – Powered from USB port or external power supply

Si5340-EVB
11. Writing a New Frequency Plan or Device Configuration to Non-Volatile
Memory (OTP)
Note: Writing to the device’s non-volatile memory (OTP) is NOT the same as writing a configuration into the Si5340 using
ClockBuilderPro on the Si5340 EVB. Writing a configuration into the EVB from ClockBuilderPro is done using Si5340
RAM space and can be done virtually unlimited number of times. Writing to OTP is limited as described below.
Refer to the Si534x/8x Family Reference Manuals and device datasheets 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 (Si5340 <—> MCU)
12.1. On-Board SPI Support
The MCU on-board the Si5340-EVB communicates with the Si5340 device through a 4-wire SPI (Serial Peripheral
Interface) link. The MCU is the SPI master and the Si5340 device is the SPI slave. The Si5340 device can also
support a 2-wire I2C serial interface, although the Si5340-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
Si5340 pass through shunts loaded on header J17. These jumper shunts must be installed in J17 for normal EVB
operation using SPI with CBPro. If testing of I²C operation via external controller is desired, the shunts in J17 can
be removed thereby isolating the on-board MCU from the Si5340 device. The shunt at JP1 (I2C_SEL) must also be
removed to select I²C as Si5340 interface type. An external I2C controller connected to the Si5340 side of J17 can
then communicate to the Si5340 device. (For more information on I²C signal protocol, please refer to the Si5340
data sheet.)
Figure 26 below illustrates the J17 header schematic. J17 even numbered pins (2, 4, 6, etc.) connect to the Si5340
device and the odd numbered pins (1, 3, 5, etc.) connect to the MCU. Once the jumper shunts have been removed
from J17 and JP1, I²C operation should use J17 pin 4 (DUT_SDA_SDIO) as the I²C SDA and J17 pin 8
(DUT_SCLK) as the I²C SCLK. Please note the external I²C controller will need to supply its own I²C signal pull-up
resistors.
Figure 26. Serial Communications Header J17
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Rev. 1.0