11. STOCK BASED COMPENSATION (Details - Compensation Expense) - USD ($) $ in Thousands |
12 Months Ended | |
|---|---|---|
Dec. 31, 2019 |
Dec. 31, 2018 |
|
| Stock-based compensation | $ 2,929 | $ 2,425 |
| Research and Development [Member] | ||
| Stock-based compensation | 839 | 558 |
| General and Administrative [Member] | ||
| Stock-based compensation | 1,956 | 1,738 |
| Selling and Marketing [Member] | ||
| Stock-based compensation | $ 134 | $ 129 |