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What's with the P2 Digikey listing - it is totally wrong! — Parallax Forums

What's with the P2 Digikey listing - it is totally wrong!

Peter JakackiPeter Jakacki Posts: 10,193
edited 2020-12-08 12:12 in Propeller 2
I hear the P2 is on Digikey.
Really!? Ok, so I take a look. From the description it sounds like some P2 Bizarro, not the P2 we know.
Why? Well this one is only Dual-core and has 16kB RAM. Go figure.
Guess that's why you need a datasheet! (Hang on, I at least did an unofficial short back in 2018)

BTW, Mouser was only just a tiny bit better but still out there with DIgikey. Maximum clock freq 25MHz etc.
p2.png
943 x 897 - 78K
p2.png 78.3K

Comments

  • JRoarkJRoark Posts: 1,215
    Rut-roh. I bet there is a story behind this. Good catch, Peter.

    Did you flag Ken? Sometimes the forum moves fast and his reading time is limited
  • tritoniumtritonium Posts: 543
    Hi

    Radiospares uk don't show them yet. https://uk.rs-online.com/web/
    They have the P1 but not the P2.

    Dave
  • ManAtWorkManAtWork Posts: 2,176
    So true. We definitely need a "real" data sheet! Even if it's "preliminary" only and lists only absolute maximum ratings and typical values...
  • Peter JakackiPeter Jakacki Posts: 10,193
    edited 2020-12-08 13:34
    While a full datasheet will have the abs max and typical values, it should list it features such as 8 cores, +300MHz clock, 512kB RAM +4kBx8 COG RAM + 64 channels A/D D/A UARTS, PWM etc etc and 3.3V operation with 1.8V core.
    Com'on Ken. I could write this part of the datasheet licketysplit while Chip gruels over the abs max etc.


    Remember I did the original pinout art that looked like a chip as well as a chip block diagram etc for the unofficial datasheet.
    P2CHIP.png
    1648 x 1652 - 320K
    p2art-9.png
    788 x 790 - 194K
    pdf
    pdf
    P2 shortform.pdf
    1M
    P2 SHORT.png
    2865 x 2022 - 1M
  • MaciekMaciek Posts: 674
    Peter Jakacki wrote: »
    ...BTW, Mouser was only just a tiny bit better but still out there with DIgikey. Maximum clock freq 25MHz etc.

    Yeah, I saw that too. We know how to read that but does anybody else ?
    Parallax should at least supply the vendors with the basic, but correct information and verify if what the vendor posts on their site matches with what they were supplied with.
  • kubakuba Posts: 94
    This may have gotten fixed since then, perhaps. Right now the DigiKey datasheet links to the Google Doc datasheet, so that's quite fine I think.
  • evanhevanh Posts: 15,916
    RAM Size 512K x 8
    I'll have some of those.
  • MaciekMaciek Posts: 674
    Maybe they meant 512 kilo x 8 bits in total and not per cog/processor ? That would be about right. A shame we need to make up things rather than being able to just read them straight out.
  • CircuitsoftCircuitsoft Posts: 1,166
    Most RAM chips are specified in bits, so if you want 8MB of RAM, you either get 64M x 1, 8M x 8, or possibly 4M x 16. It's a reference to the native word size of the RAM. Since HUB ram is byte-addressable, it makes 512K x 8 the best description of it.
  • jmgjmg Posts: 15,173
    Peter Jakacki wrote: »
    While a full datasheet will have the abs max and typical values, it should list it features such as 8 cores, +300MHz clock, 512kB RAM +4kBx8 COG RAM + 64 channels A/D D/A UARTS, PWM etc etc and 3.3V operation with 1.8V core. ...

    Yes, a data sheet is needed badly, with actual specs engineers can design to.
    The 300+MHz could go into a data sheet, but only in an 'overclock' column.
    The guaranteed min needs to be what is defined. (whatever OnSemi actually test them to ) Was that 180MHz (PVT), or a bit below that ?

  • Wuerfel_21Wuerfel_21 Posts: 5,053
    edited 2020-12-16 19:47
    Circuitsoft wrote: »
    Since HUB ram is byte-addressable, it makes 512K x 8 the best description of it.

    Not necessarily. Most discrete 16 bit wide RAM chips are byte addressable (or rather, have byte enables, which is how Hub RAM works internally, too). The 32 bit bandwidth is probably the more interesting aspect.

    "8 x 16K x 32" is probably the best way to describe P2 hub RAM. That'd also have the advantage of standing out in the parametric search tools ;)
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