70 xoroshiro64
70 : xoroshiro64
- Author: Vivek Chiranjit
- Description: xoroshiro TRNG
- GitHub repository
- Open in 3D viewer
- Clock: 25000000 Hz
How it works
This design implements a lightweight xoroshiro64+ random number generator with ring oscillator (RO) noise injection to provide entropy.
The generator maintains two 32-bit internal states (s0 and s1). On each enabled clock cycle:
-
A 32-bit random word is generated using a ripple-carry adder:
random_word = s0 + s1 -
The xoroshiro64+ state update equations compute the next values of
s0ands1. -
The RO noise input is XORed into the least significant bit of
s0to introduce true randomness. -
The generated 32-bit word is loaded into a serializer.
-
The serializer shifts out one bit per clock on
serial_out.
A pulse on valid_out indicates the start of a new 32-bit random word.
The internal state can also be seeded through an 8-bit seed-loading interface.
How to test
- Apply a clock to
clk. - Release reset by setting
rst_n = 1. - Set
enable = 1. - Provide a changing signal on
ro_noise(for example, from a ring oscillator). - Monitor
serial_out. - Observe
valid_out; it pulses high when a new 32-bit random word begins shifting out. - Optionally load custom seeds using
seed_data,seed_wen, andseed_sel.
External hardware
- 1-bit Ring Oscillator (RO) noise source connected to
ro_noise. - No other external hardware is required.
IO
| # | Input | Output | Bidirectional |
|---|---|---|---|
| 0 | seed data | serial_out_w | seed_sel |
| 1 | seed data | valid_out_w | seed_sel |
| 2 | seed data | osc_ro_fast | seed_sel |
| 3 | seed data | osc_ro_slow | seed_wen |
| 4 | seed data | enable | |
| 5 | seed data | ro_noise | |
| 6 | seed data | ||
| 7 | seed data |