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P2 + FT9xx ? — Parallax Forums

P2 + FT9xx ?

RaymanRayman Posts: 14,646
edited 2019-10-11 20:31 in Propeller 2
Since it looks like we still need an FTDI chip for the USB to serial interface, I'm thinking about upgrading it to an FTDI FT9xx microcontroller.
If I'm seeing it right, it can do the USB-serial bridge plus a lot more...
https://brtchip.com/ft93x/

Programming is probably a nightmare, but only have to do it once maybe...

BTW: The older FT900 is really big, but can do ethernet and parallel-camera interface, which is interesting...

Comments

  • jmgjmg Posts: 15,173
    edited 2019-10-11 22:09
    How much USB speed do you need ?
    I looked briefly at FT9x, and FWIR, it had issues like SysCLK is only 100MHz, and data says 'Maximum UART data bit rate of 8 Mbit/s', so seems limiting.

    For P2D2, Peter has included EFM8UB3 with FS-USB, that's very small and low cost, and very flexible.
    I've now got large buffers working in that, to make the USB-UART a little more P2 useful.

    On this, bursts of 8M.8.n.2 and even 12M.8.n.2 up to 1536 bytes look possible P2 -> UB3 -> PC
    PC->UB3->P2 can be any 24M/N baud rate, but average rates limited by USB & drivers.

    Sustained speeds are USB/Driver limited, and 2.4~4Mbd seem practical.

    If you need 12MBd continual duplex, then HS-USB parts like FT232H/FT2232H (bigger buffers) etc would be needed, or a better MCU with HS-USB & good uarts.

    On better MCUs, there is
    NUC505DLA HS-USB 100MHz 512k SPI flash in package, LQFP48 1000+ $1.74
    This has 64 byte FIFOs and Max Baud is a little vague, maybe 100MHz/(9 +2) which is a little uncommon.... ?

    I did notice NXP have MIMXRT1011DAE5A flashless part, for $2.0496/1k, Eval Board $10.10 until dec 2019
    That's 500MHz core, but data says "Programmable baud rates up to 5 Mbps" and has modest 4 Byte FIFOs on UARTs*, so the core is great, but the UARTs rather ordinary.
    * Maybe DMA can be used to ease the UART FIFO issue ?
    The RT1010 has quite good looking i2s links, with larger fifos, they could be another choice ?

    Addit: I was going to suggest FT4222 as the best priced HS-USB link, SPI/QuadSPI, but I notice the prices have leapt from $1.53/1k for rev C parts, to a strange flat $5 for rev D at Mouser & Digikey.
    That's quite a hike, to be more than FT232H and FT2232H !
  • RaymanRayman Posts: 14,646
    edited 2019-10-11 22:22
    If you want speed, you could use the QSPI interface... Should do 100 MBPS bursts...

    Says it is rated at 310 DMIPS. Not exactly sure what that means, but sounds good.

    I really like that it has an RTC built in.

    Also, I might look into using the SD interface. Says it does 4-bit mode. And does SDXC, which I think means it has software for exFAT formatted cards.

    There's a lot there that I like. I just dread programming... I tried using Vinculum once and got bogged down in the programming...
  • jmgjmg Posts: 15,173
    Rayman wrote: »
    If you want speed, you could use the QSPI interface... Should do 100 MBPS bursts...

    Says it is rated at 310 DMIPS. Not exactly sure what that means, but sounds good.

    I really like that it has an RTC built in.

    Also, I might look into using the SD interface. Says it does 4-bit mode. And does SDXC, which I think means it has software for exFAT formatted cards.

    There's a lot there that I like. I just dread programming... I tried using Vinculum once and got bogged down in the programming...

    Hehe, yes, the price is quite good, but the 2000 page user manual is a bit daunting...
    Pity they do not offer smaller packages than TQFP80 yet ?
    I see it has a 64K ROM, and NXP parts used to offer boot from USB, tho I can see only serial mentioned in summaries. (this I think is a freescale pathway device ?)
  • RaymanRayman Posts: 14,646
    edited 2019-10-11 22:55
    I think it has a flash that is copied to ram on boot so that program runs from ram and not flash (zero wait states as they say).

    There's a QFN-48 package, but that one doesn't have the RTC. I'm looking at the 56 Pin QFN (FT931Q).

    One cool thing is that you can update the flash via a file on USB thumbdrive. At least, I think that's what DFU means...
  • jmgjmg Posts: 15,173
    Coming down a notch from the RT1010, (for smaller packages, still HS-USB ) I find

    https://www.nxp.com/products/processors-and-microcontrollers/arm-microcontrollers/general-purpose-mcus/lpc5500-cortex-m33:LPC5500_SERIES

    Still road-map stuff, for many, but there are prices showing on LPC5526JBD64K 150MHz 256 KBF 144 KBR at $2.45/1k, in HTQFP64,
    and there is an Eval Board for the super-set part LPC55S69-EVK at ~$41

    and they mention coming are 
    LPC551x/S1x	Baseline with USB & CAN-FD	Optional	HS/FS USB, CAN-FD, HS SPI,FlexComm (8)	-	HVQFN48 HTQFP64 LQFP100 VFBGA98
LPC550x	        Low cost with HS USB	        -	        HS/FS USB, HS SPI, FlexComm (8)	        -	HTQFP64 LQFP100
    Unusual the lowest cost one, seems to skip HVQFN48, but maybe that's a typo ? Prices should be under the LPC5526 indication.
    Being LPCxx stable, I think this series has 128K ROM and can boot from USB ?
  • RaymanRayman Posts: 14,646
    It's the programming with all of these that is the issue...

    I'm hoping I can copy and paste from FTDI examples to get this one going...
    If not, might have to re-evaluate...
  • jmgjmg Posts: 15,173
    Rayman wrote: »
    It's the programming with all of these that is the issue...

    I'm hoping I can copy and paste from FTDI examples to get this one going...
    If not, might have to re-evaluate...

    How fast do you need this serial link ?
    EFM8UB3 is simplest/cheapest/most flexible, and if you need more speed, the FT232H, is cheaper and faster than FT93x - no code needed.
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