CHACHA_BLOCK_CNT_LSB

nRF5340 Product Specification

Address offset: 0x3B8

Store the LSB value of the block counter, in order to support suspend/resume of operation

The two first words (n) in the last row of the cipher matrix are the block counter. At the end of each block (512b), the block counter for the next block is written by HW to register CHACHA_BLOCK_CNT_LSB and register CHACHA_BLOCK_CNT_MSB. If starting a new message the block counter must also be reset.

Bit number 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
ID A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A
Reset 0x00000000 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
ID R/W Field Value ID Value Description
A

RW

VALUE

This register holds the ChaCha block counter bits [31:0] and must be read and written during respectively suspend and resume operations.