PoLabs PoScope Basic2
The PoLabs PoScope Basic2 is a 16-channel, 8MHz, USB-based logic analyzer (plus oscilloscope, signal/pattern generator, and more).
See PoLabs PoScope Basic2/Info for some more details (such as lsusb -vvv output) on the device.
Components
- Silicon Labs C8051F32x: 8051-based microcontroller with USB and 10bit ADC (datasheet)
- Omron G3VM-401G: Analog switching MOS FET relay (datasheet)
- Analog Devices AD8544: CMOS RRIO quad general-purpose opamp (datasheet)
- Texas Instruments HC74 87K G4 A6EK (TODO)
Photos
Protocol
Starting a sampling run
The command for starting an acquisition is a USB control transfer (request type: vendor-specific, request: 0x07, value: 0xffa0, index: 0x0000, length: 9).
The 9 bytes of data:
Byte | Description | Comments |
---|---|---|
0 | Samplerate divider | (see table below) |
1 | ||
2 | ||
3 | ||
4 | ||
5 | Trigger mask | Bit 0 is the mask for probe 0, bit 7 is the mask for probe 7. The same byte is used as trigger mask byte for bus A or bus B (only one at a time is possible). |
6 | ||
7 | ||
8 |
Stopping a sampling run
Sample rates
8MHz - 4MHz:
Buffer size is 128 bytes, only bus A is available, ...
Samplerate | Divider |
---|---|
8 MHz | 0x00 |
6 MHz | 0x01 |
4 MHz | 0x02 |
2.6MHz - 2MHz:
Buffer size is 1160 bytes, only bus A is available, ...
Samplerate | Divider |
---|---|
2.6 MHz | 0x03 |
2 MHz | 0x04 |
1MHz - 600kHz:
Buffer size is 1544 bytes, ...
Samplerate | Divider |
---|---|
1 MHz | 0x05 |
900 kHz | 0x05 |
800 kHz | 0x05 |
700 kHz | 0x05 |
600 kHz | 0x05 |
500kHz and lower:
Buffer size is only limited by the PC memory, ...
Samplerate | Divider |
---|---|
500 kHz | 0x05 |
400 kHz | 0x05 |
300 kHz | 0x05 |
250 kHz | 0x06 |
200 kHz | ... |
150 kHz | ... |
100 kHz | ... |
90 kHz | ... |
80 kHz | ... |
70 kHz | ... |
60 kHz | ... |
50 kHz | ... |
40 kHz | ... |
30 kHz | ... |
25 kHz | ... |
20 kHz | ... |
10 kHz | ... |
9 kHz | ... |
8 kHz | ... |
7 kHz | ... |
6 kHz | ... |
5 kHz | ... |
4 kHz | ... |
3 kHz | ... |
2.5 kHz | ... |
2 kHz | ... |
1 kHz | ... |