System Boot And Nvm Programming; Startup Overview - Silicon Laboratories Si4010-C2 Manual

Crystal-less soc rf transmitter

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Si4010-C2

24. System Boot and NVM Programming

The device does not include a Flash memory for permanent code or data storage. Instead, the device con-

tains 4. 5kB of RAM, which can serve as a unified CODE and XDATA RAM memory. The device contains

8 kB of NVM (OTP) memory for user code and data storage. Small part of the NVM is reserved for Silicon

Labs factory use and is not available to a user. In general more than 7 kB of NVM will be available for user

application use.

The code cannot be run directly from NVM, since it is not mapped directly to the CPU address space.

Instead, upon device reset, the device goes through a boot process during which the factory chip configu-

ration and the user application code and data is copied from NVM to the CODE/XDATA RAM. Only after

the boot process finishes the user code starts being executed from CODE/XDATA RAM address 0x0000.

Therefore upon reset the device does not execute the user code immediately, but only after the boot pro-

cess finishes. The time in between the device wakeup, either caused by cycling the power or waking up

from the shutdown mode by button press, depends on the size of the user code load.

In general the startup time is about 2ms of fixed time plus 3.6 ms per 1 kB of user application code. For

example, 4 kB application will incur

Tstartup = 2 ms + 3.6 ms x User_KB = 2 ms + 3.6 ms x 4 = 16.4 ms

startup time before the user application starts being executed.

For debugging purposes user will not program the NVM, but will use the RAM for code development. In

that case the device will only contain factory settings and go through much shorter startup routine, which

would take less than 2 ms to finish.

Rev. 1.0

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