Datasheet

To write to the HSSR register the KEY field must be set to 0xCA. The CDOFF field in the HSSR

■ 0x00.0000 – No request and/or the previous request completed successfully

■ 0xFF.FFFF – No request and the previous request failed

■ Anything else – The offset into SRAM of a HSSR request structure

During the HSSR routine, if anything else is seen in the CDOFF field, then the offset is examined for

validity and the structure it points to is examined for validity. If either is invalid, the request has failed

and 0xFF.FFFF is written to the CDOFF field.

The offset is valid if all the following conditions are met:

■ The CDOFF value is word aligned (that is, the two LSBs are both zero)

■ The CDOFF value is at least 0x2000.4000

■ The CDOFF value is at most 0x2003.FFF0

Once a valid HSSR offset is determined, the following structure is examined in the SRAM that is

indicated by the CDOFF field in the HSSR register. In order to initiate a return-to-factory settings

function, the data structure must be as follows:

■ Request (32 bits) = 0xFEED.0001

■ Data 1 (32 bits) = 0x0201.0100

■ Data 2 (32 bits) = 0x0D08.0503

■ Data 3 (32 bits) = 0x5937.2215

If the data bytes are correct, then the device is returned to factory condition. During the

return-to-factory settings function, the following events occur:

■ The RAM is erased in the Hibernation module

■ The system SRAM is erased

■ The FMPPEn registers are set to 0xFFFF.FFFF (to allow a Flash erase operation to occur)

■ The EEPROM pages are erased

■ A mass-erase of the flash array occurs

■ The BOOTCFG register is written with 0xFFFF.FFFE

Once the return-to-factory settings sequence is completed, the CDOFF field of the HSSR register is

written with 0x00.0000, indicating a successful completion and activating a system reset.

5.3 Initialization and Configuration

The PLL is configured using direct register writes to the PLLFREQn, MEMTIM0, and PLLSTAT

registers. The steps for initializing the system clock from POR to use the PLL from the main oscillator

is as follows:

December 13, 2013256

Texas Instruments-Advance Information

System Control