Measure Firmware Memory Read Cycle Waveform With Oscilloscope - Page 1
Forum section: electronics / beginners

author: 2X
author_rank: Frequent Contributor
timestamp: February 01, 2025, 08:34:18 pm
content: Hello,I have the SST49LF004B-33-4C-NH bios chip on a motherboard that I have for making tests and I want to learn how can I measure the "Measure Firmware Memory Read Cycle Waveform" with my oscilloscope. I have the R&S®RTC1002 oscilloscope + MSO with the options "R&S®RTC-K1" & "R&S®RTC-K2" & "R&S®RTC-K3".Because I have never use MSO and done something like this before and i don't want to damage something, what I have to do in order to see the below waveform (figure 4) on my oscilloscope (like pin connections, oscilloscope triggering and decoding protocol type etc)? If you know an article or video or whatever I could read to learn about it please tell me.The LCLK and LFRAME# I beleive I could se them with just the two channels but haw can I get this representation of the LAD[3:0] like the figure 4 of the datasheet shows?R&S®RTC1000 Digital Oscilloscope User Manualhttps://www.batronix.com/files/Rohde-&-Schwarz/Oscilloscope/RTC1000/RTC_UserManual_en_05.pdf

author: BillyO
author_rank: Super Contributor
timestamp: February 01, 2025, 08:56:10 pm
content: Trigger on LFRAME going low and record the the 4 address lines and the 8 data lines.How many lines does your MSO have?

author: 2X
author_rank: Frequent Contributor
timestamp: February 01, 2025, 09:12:48 pm
content: Quote from: BillyO on February 01, 2025, 08:56:10 pmOnly these pins that I have highlight at the below picture is where I have to connect the pins of the MSO in order to see the figure 4 of the datasheet or I need more pins to measure (sorry, but I didn't understand something you wrote... why to record the "8 data lines"?It has 8-Channels (D0-D7).

author: BillyO
author_rank: Super Contributor
timestamp: February 01, 2025, 09:22:52 pm
content: Hmm, you really need 12 if you want to see all the communication. With only 8 I'd record the data lines. Of course yo have your analog channels too.

author: 2X
author_rank: Frequent Contributor
timestamp: February 01, 2025, 09:31:53 pm
content: Quote from: BillyO on February 01, 2025, 09:22:52 pmIf I want to see all the communication as I understand I want:1pin for LCLK (maybe this is not very critical for in order to measure the below)1 pin for LFRAME4 pins for LAD[3:0]8 pins for DQ7-DQ0Totally: 14pins or 13pins (without LCLK)If only I want to see what the figure 4 shows I need:1pin for LCLK (maybe this is not very critical for in order to measure the below)1 pin for LFRAME4 pins for LAD[3:0]Totally: 6pins or 5pins (without LCLK)Sorry if am I asking something that is very obvious.

author: BillyO
author_rank: Super Contributor
timestamp: February 01, 2025, 09:35:14 pm
content: Yes, you'd need at least 13 channels. LCLK is not critical at all, but if you have 14+ channels, why not?If you go for the 5 channel option you will see none of the data being transferred. All you will know is what register/command is being addressed.

author: 2X
author_rank: Frequent Contributor
timestamp: February 02, 2025, 08:19:21 am
content: Quote from: BillyO on February 01, 2025, 09:35:14 pmMaybe I made a mistake. As I re-check the datasheet the pins LAD0=DQ0, LAD1=DQ1, LAD2=DQ2, LAD3=DQ3 so,1pin for LCLK (Can I attach it on CH1?)1 pin for LFRAME (Can I attach it on CH2?)4 pins for LAD[3:0] (4 pins from logic probe)4 pins for DQ7-DQ4 (4 pins from logic probe)Totally: 8pins from logic probe & 2pins from Analog/Digital Oscilloscope Channels

author: 2X
author_rank: Frequent Contributor
timestamp: February 04, 2025, 11:48:43 pm
content: Quote from: 2X on February 02, 2025, 08:19:21 amIf you please could somebody tell me if am I correct in the above that I wrote in my last post?

author: BillyO
author_rank: Super Contributor
timestamp: February 04, 2025, 11:51:46 pm
content: I do not see what benefit you would have from just looking at the 4 MSB of the data.

author: artag
author_rank: Super Contributor
timestamp: February 05, 2025, 11:26:19 am
content: Quote from: BillyO on February 04, 2025, 11:51:46 pmIt depends why you want the reading.If you want to verify the data then yes, you need all 8. But you can do it twice and capture both halves.,If you want to verify the timing (and can trust that all 8 become active at the same time) then 4 may be fine.

author: 2X
author_rank: Frequent Contributor
timestamp: February 05, 2025, 04:24:59 pm
content: I would like to learn to use the logic analyzer and to see the reading data in this form that is the below picture. I don't know if this display form (in the red circle) have a name and also this is an SPI communication.