Documentation for BLE

Hi.
In the DA14580_DS_v1.62.pdf datasheet, I see references to "Refer also to BLE_CNTL2_REG[BLE_CLK_SEL]."
However, I can't find any information about that. Not in the same pdf nor in any of the RivieraWaves pdfs at the Resources page.
I'd also like documentation about all the RF_* registers. For example, I can't figure out what does this code mean in the arch_main.c sample.

SetWord16(RF_LNA_CTRL1_REG, 0x24E);
SetWord16(RF_LNA_CTRL2_REG, 0x26);
SetWord16(RF_LNA_CTRL3_REG, 0x7);
SetWord16(RF_REF_OSC_REG, 0x29AC);
SetWord16 (RF_RSSI_COMP_CTRL_REG 0 x7777);
SetWord16(RF_VCO_CTRL_REG, 0x1);