#apertus IRC Channel Logs

morning folks!

good day

hi Dev_, i've replied to your email yesterday already, please check your spam folder, as Supragya retrieved it from his

Meeting Time?

okay, sorry for being late ...

no problem

in both tasks, there is a need to program a MachXO2 which is not directly accessible

the plugin modules (USB 3.x) have to be programmed through the low speed GPIO pins of the plugin interface

and for the routing fabrics, it's even worse, there we do not even have a way to 'connect' to the JTAG port from outside, except for a tiny header which can be connected to wires on dedicated hardware

Aren't the RFs programed by PIC microcontroller?

any idea how the programming works there?

or to rephrase the question, do you have an idea how you could use PIC16s to program a MachXO2 via JTAG?

Maybe I am wrong here

the details are a little trickier, but that's what I'm going to explain

the other two are 'programming' pins called PCLK (clock) and PDAT (data)

so we could for example program the PIC16 and then use an UART protocol to 'talk' to the PIC16

so there are two protocols spoken on those two wires (PDAT, PCLK)

and once the PIC16 is running, the second protocol, I2C, is active

showing up at a range of addresses, which all have specific functions

so, any idea how we can do JTAG over I2C?

aSobhy: you around?

any idea how JTAG works?

and SDA to be TDI ?

we have the situation that a full JTAG port (TMS, TDI, TDO, TCK) is connected to the PIC16 at one side

the problem now is to 'control' the JTAG, via the PIC, but do this over I2C :)

so any idea how JTAG works?

TMS & TCK are shared

okay, so there is a clock (TCK) and there is data

and there is one output called TDO

at the same time the data from the TDI shift register is shifted out via TDO

it controls a state engine which basically tells the device what kind of data it will receive or transmit

you should definitely take a closer look in the next few days :)

and while TMS and TDI are basically operating in parallel, thanks to the state engine, we can either send TMS data or TDI data (and keep the other line constant)

as I2C is basically 8 bit data

this is also implemented in the I2C slave in the PIC, so certain addresses result in either a full byte or less than eight bit being sent (or retrieved) via JTAG

we will test this via a remote session in the next few days once the remote Betas are hooked up

Background mode and off mode

well, yeah, that's not exactly what I meant but it is related

and as most FPGA, the active configuration is always based on the SRAM

so programming can be done in two ways, by programming the flash and by directly loading the bitstream into SRAM

the MachXO2 have a somewhat limited amount of program cycles for the flash

now while the scripts and PIC code are sufficient for aSobhy's task (programming the routing fabrics)

any idea why?

well, you can do that when you have the plugin in the breakout board (that's what it is for)

what would be the process/path there?

We will use a special pass through code on RFs

<Bertl "what would be the process/path t"> Till aSobhy doesn't completes the bidirectional protocol

apurvanandan[m]: do you also remember how the pass through works?

why not both :)

that is basically correct except for a small detail

can you check the schematics which pins of RFE are connected to the plugin slots?

Haven't opened schematics of main board yet. It will take time.

what is programmer apurvanandan[m] talking about ?!

about programming the MachXO2 on the USB 3.0 plugin module

the plugin modules each also contain a MachXO2 (the USB3 ones) which work as gearwork for the FTDI used to connect via USB

ah okay

(and a three hop via the PIC16)

yep, the Zynq then can send (and receive) JTAG data via the MachXO2 interface on the main board

no problem, it's always good to get an idea what the other students are doing :)

so I'll change the JTAG to be implemented first

yes

but it is definitely more complex than I2C to get started with

okay, I guess apurvanandan[m] might appreciate it :)

They are connected to Jtag programming pins directly

Of usb plugin module, on RFE I am searching what are those pins of MachXO2

Yeah, they are GPIOs

PCIE_N_IO* on RFE

okay, except for a small detail, the plugin slots are on the 'West' side not the 'East', so it is RFW not RFE :)

So JTAG protocol is similar to SPI, hence RFE simply forwards it

To the spi

and the pass through is actually slighly different in the plugin programming case

Yes , that's confusing

(besides the JTAG pins)

okay, so that's been a lot for today, but we have to increase the pace now that we entered the coding phase

please read up on JTAG and I2C for this purpose and check the schematics again

of course, please share

okay, apurvanandan[m], any preferences?

http://xilinx.eetrend.com/files-eetrend-xilinx/forum/201407/7408-13218-xilinx_serial_io_101_gao_su_chuan_xing_ru_men_.pdf

This paper compares two methods of word recombination ie using delay component and using fifo: http://sci-hub.tw/https://doi.org/10.1109/TCSII.2015.2468992

I would prefer Friday actually :)

Okay fine

of course, you can already start with a bunch of things you learned

like for example the PRNG and BER calculations

PRNG is already implemented by you though

best combine it with a testbench

Also do we need to follow our timeline exactly, like do every thing in same order?

I mentioned to start with ft601q controller

And also mentioned to show that for the phase 1 evaluation ^^'

I presume you already know the FT60x inside out

(at least theoretically)

how's that?

still 2 exams (Thursday and Sunday)

anyway, GSoC is not simple, so try your best there as well as with any other exams or tasks

but as you both will need the test framework, it might make things a lot simpler to work together

*halve

Ok will chat with aSobhy and start coding from tomorrow.

What type and for what( for some official reason?)

kind of overview/summary of the datasheet, how the thing works and what it does ... how the interface looks like

for the remote meeting we will use ssh/screen

so if you haven't done so already, send me your public ssh keys

And how will I present that?

however you like ... IRC chat, conversional style or if you prefer with (PDF) slides or whatever you like

OK, thanks :)

hhhhhhhh yeah I know

`I have sent my ssh key

<Bertl "okay, any unanswered questions l"> Nope, Thanks for your time!

Bertl: how can we save the meeting chat

so you can look it up on irc.apertus.org

google groups

I think you don't have time to do so I can help :)

OK,

my pleasure!