Difference between revisions of "Braintechnology USB-LPS"

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(Start documenting the USB-LPS protocol.)
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=== Starting a sampling run ===
=== Starting a sampling run ===


TODO.
The host seems to send: 0x00 0x01 0x00 0x00 0x00
 
=== Stopping a sampling run ===
 
The host seems to send: 0x00 0x00 0x00 0x00 0x00


=== Sample rates ===
=== Sample rates ===


Sampling with 8 probes:
<table><tr valign="top"><td>
 
'''Sampling with 8 probes:'''


{| border="0" style="font-size: smaller"
{| border="0" style="font-size: smaller"
Line 33: Line 39:
!Samplerate
!Samplerate
!Divider
!Divider
!Other byte
|- bgcolor="#eeeeee"
|- bgcolor="#eeeeee"
| 24 MHz
| 24 MHz
| 0x01
| 0x01
| 0xee
|- bgcolor="#dddddd"
|- bgcolor="#dddddd"
| 16 MHz
| 16 MHz
| 0x02
| 0x02
| 0xee
|- bgcolor="#eeeeee"
| 15 MHz
| 0x01
| 0xae
|- bgcolor="#dddddd"
| 12 MHz
| 0x03
| 0xee
|- bgcolor="#eeeeee"
| 10 MHz
| 0x02
| 0xae
|- bgcolor="#dddddd"
| 8 MHz
| 0x05
| 0xee
|- bgcolor="#eeeeee"
| 6 MHz
| 0x07
| 0xee
|- bgcolor="#dddddd"
| 5 MHz
| 0x05
| 0xae
|- bgcolor="#eeeeee"
| 4 MHz
| 0x0b
| 0xee
|- bgcolor="#dddddd"
| 3 MHz
| 0x0f
| 0xae
|- bgcolor="#eeeeee"
| 2.5 MHz
| 0x0b
| 0xae
|- bgcolor="#dddddd"
| 2 MHz
| 0x17
| 0xee
|- bgcolor="#eeeeee"
| 1.5 MHz
| 0x1f
| 0xae
|- bgcolor="#dddddd"
| 1 MHz
| 0x2f
| 0xee
|- bgcolor="#eeeeee"
|- bgcolor="#eeeeee"
| ...
| 800 kHz
| ...
| 0x1f
| 0xee
|- bgcolor="#dddddd"
| 750 kHz
| 0x3f
| 0xee
|- bgcolor="#eeeeee"
| 600 kHz
| 0x4f
| 0xee
|- bgcolor="#dddddd"
| 500 kHz
| 0x5f
| 0xee
|- bgcolor="#eeeeee"
| 400 kHz
| 0x77
| 0xee
|- bgcolor="#dddddd"
| 300 kHz
| 0x9f
| 0xee
|- bgcolor="#eeeeee"
| 250 kHz
| 0xbf
| 0xee
|- bgcolor="#dddddd"
| 200 kHz
| 0xef
| 0xee
|- bgcolor="#eeeeee"
| 150 kHz
| 0xc7
| 0xae
|- bgcolor="#dddddd"
| 120 kHz
| 0xf9
| 0xae
|}
|}


Sampling with 16 probes:
</td><td>
 
'''Sampling with 16 probes:'''


{| border="0" style="font-size: smaller"
{| border="0" style="font-size: smaller"
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| ...
| ...
|}
|}
</td></tr></table>


=== Sample format ===
=== Sample format ===


TODO.
TODO.
=== Triggers ===
Not relevant to the protocol, happens purely in software.

Revision as of 02:23, 5 January 2012

Braintechnology USB-LPS
Braintechnology USB-LPS, PCB front
Braintechnology USB-LPS, PCB front details
Braintechnology USB-LPS, PCB back

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

The host seems to send: 0x00 0x01 0x00 0x00 0x00

Stopping a sampling run

The host seems to send: 0x00 0x00 0x00 0x00 0x00

Sample rates

Sampling with 8 probes:

Samplerate Divider Other byte
24 MHz 0x01 0xee
16 MHz 0x02 0xee
15 MHz 0x01 0xae
12 MHz 0x03 0xee
10 MHz 0x02 0xae
8 MHz 0x05 0xee
6 MHz 0x07 0xee
5 MHz 0x05 0xae
4 MHz 0x0b 0xee
3 MHz 0x0f 0xae
2.5 MHz 0x0b 0xae
2 MHz 0x17 0xee
1.5 MHz 0x1f 0xae
1 MHz 0x2f 0xee
800 kHz 0x1f 0xee
750 kHz 0x3f 0xee
600 kHz 0x4f 0xee
500 kHz 0x5f 0xee
400 kHz 0x77 0xee
300 kHz 0x9f 0xee
250 kHz 0xbf 0xee
200 kHz 0xef 0xee
150 kHz 0xc7 0xae
120 kHz 0xf9 0xae

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.

Triggers

Not relevant to the protocol, happens purely in software.