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Commit | Line | Data |
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1 | ------------------------------------------------------------------------------- | |
2 | GIGABYTE 6VLE-VXL I2C data | |
3 | ------------------------------------------------------------------------------- | |
4 | ||
5 | This is an example capture of I2C traffic on a DDR SDRAM's EEPROM chip, for | |
6 | Serial Presence Detect (SPD) data. The 512MB DDR RAM module was inserted | |
7 | in a GIGABYTE 6VLE-VXL mainboard. After the capture was started, the board | |
8 | was powered-on, thus the captured data corresponds to the BIOS code which | |
9 | reads the RAM module's EEPROM contents (in order to properly initialize | |
10 | the RAM). | |
11 | ||
12 | Additionally, it turned out that on the same I2C bus, there is an additional | |
13 | I2C device, the ICS950908 "Programmable Timing Control Hub for P4" (a clock | |
14 | generation chip). The capture also contains the I2C-based configuration of | |
15 | that chip by the BIOS. | |
16 | ||
17 | Details: | |
18 | https://en.wikipedia.org/wiki/Serial_presence_detect | |
19 | http://pdf1.alldatasheet.com/datasheet-pdf/view/90645/ICST/ICS950908.html | |
20 | ||
21 | ||
22 | Logic analyzer setup | |
23 | -------------------- | |
24 | ||
25 | The logic analyzer used was a Saleae Logic (at 2MHz): | |
26 | ||
27 | Probe I2C pin | |
28 | ------------------- | |
29 | 1 (black) SCL | |
30 | 4 (orange) SDA | |
31 | ||
32 | ||
33 | Data | |
34 | ---- | |
35 | ||
36 | The sigrok command line used was: | |
37 | ||
38 | sigrok-cli -d 0:samplerate=2mhz --time 10s -o <filename> | |
39 |