Braintechnology USB-LPS
Revision as of 01:39, 5 January 2012 by Uwe Hermann (talk | contribs) (Start documenting the USB-LPS protocol.)
The Braintechnology USB-LPS is a Cypress FX2 based 16-channel, 24MHz, USB-based logic analyzer and signal/pattern generator.
See Braintechnology USB-LPS/Info for some more details (such as lsusb -vvv output) on the device.
Components
- Cypress CY7C68013A-56PVXC (FX2)
- Atmel ATTiny13-20SU
- LD33 (3.3V voltage regulator)
- 24MHz crystal
Protocol
Firmware upload
The FX2 firmware (3072 bytes in size) is uploaded before every sampling run. Certain bytes in the firmware differ depending on the selected sampling rate.
Starting a sampling run
TODO.
Sample rates
Sampling with 8 probes:
| Samplerate | Divider |
|---|---|
| 24 MHz | 0x01 |
| 16 MHz | 0x02 |
| ... | ... |
Sampling with 16 probes:
| Samplerate | Divider | Other byte |
|---|---|---|
| 12 MHz | 0x03 | 0xee |
| 10 MHz | 0x02 | 0xae |
| 8 MHz | 0x05 | 0xee |
| 6 MHz | 0x07 | 0xee |
| 5 MHz | 0x05 | 0xae |
| 4 MHz | 0x0b | 0xee |
| ... | ... | ... |
Sample format
TODO.