SPI
RK3399 has 6x SPI controllers with the following features:
- Support master and slave mode, software-configurable
- DMA-based or interrupt-based operation
- Embedded two 32x16bits FIFO for TX and RX operation respectively
On Helios64, the buses are divided into three types: Not Available, System (internal bus) and User (external bus).
| Bus | Usage | Remarks |
|---|---|---|
| 0 | Not Available | |
| 1 | System | Bootable SPI Flash |
| 2 | User | User Application |
| 3 | Not Available | |
| 4 | Not Available | |
| 5 | System | Reserved for Production use only |
Internal Bus¶
| Bus | Chip Select | Device | Remarks |
|---|---|---|---|
| 1 | 0 | W25Q128JV | Bootable SPI Flash |
| 5 | 0 | W25X20CL | SATA Controller ROM |
Bootable SPI Flash¶
Helios64 is equipped with Winbond W25Q128JV 3V 128M-Bit Serial Flash Memory as a Bootable SPI NOR Flash.
This flash contains
- Preloader & bootloader
| Binaries | Offset | Remarks |
|---|---|---|
| Preloader | 0x0040 | U-Boot TPL & SPL |
| Bootloader | 0x4000 | U-Boot & ATF |
- Electronic nameplate data in Security Register
External Bus¶
| Bus | Chip Select | Remarks |
|---|---|---|
| 2 | 0 | User Application |
SPI Bus for user application is exposed on UEXT header (P2)
| Pin | Signal Name |
|---|---|
| 7 | MISO |
| 8 | MOSI |
| 9 | SCK |
| 10 | SSEL |
Note: The pin voltage level is 3.3V.
Last update: May 2, 2020