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smartpin SPI (bidirectional) sample code? — Parallax Forums

smartpin SPI (bidirectional) sample code?

Mark_TMark_T Posts: 1,981
in Propeller 2
Had a bit of a search but didn't find anything obvious, I'm sure someone has some examples of this to avoid re-inventing the wheel?

Comments

  • evanhevanh Posts: 16,354
    As in single data pin, or just using both DI and DO in conversation?
  • evanhevanh Posts: 16,354
    Cluso will have routines in the ROM monitor for talking with SPI Flash chips.
  • Cluso99Cluso99 Posts: 18,069
    In the ROM monitor there are three vesrions of SPI code...
    Chips booter which accesses the FLASH. He uses separate send and receive routines.
    My SD booter which uses a combine send/receive routine with various entry points depending on what you are needing to do. Easiest way, search for the label SENDFF.
    Peters TAQOZ. YOu will have to ask Peter.
  • Mark_TMark_T Posts: 1,981
    edited 2019-02-27 15:16
    I think all the ROM monitor booter stuff is bitbanged, not smartpin.
  • Cluso99Cluso99 Posts: 18,069
    Yes. Didn’t realise you wanted smartpins mode.
  • Mark_TMark_T Posts: 1,981
    Well it seems like a thing that smartpins should be doing (if only to make the clock speed easily configurable).
    But bit bashing is useful too :)
  • jmgjmg Posts: 15,190
    Mark_T wrote: »
    Well it seems like a thing that smartpins should be doing (if only to make the clock speed easily configurable).
    But bit bashing is useful too :)

    Smart pins are used in the UART side, because highest baud rate helps there, and the buffering buys time to allow SPI bit-bash.
    I think one reason to KISS on SPI was to keep the boot silicon minimal, and so lower the risk of smart pin flaws causing dead-in-water outcomes...
  • RaymanRayman Posts: 15,039
    It'd be interesting to see if using Smartpin + Interrupt would let you juggle several I/O things in one cog.

    Things like SPI and I2C and serial are so slow compared to P2 clock speed, seems very doable...
  • msrobotsmsrobots Posts: 3,709
    I have a two port async-serial driver with buffers in LUT using smart pins and interrupts. The smart pins easy outrun the HUB/LUT transfer, with up to sys clock baud, without issues. not sure to what to connect with 180Mbaud, but the pins work and the interrupts do also.

    That speed also outruns my Scope, so no pictures...

    Enjoy!

    Mike
  • Cluso99Cluso99 Posts: 18,069
    Nice :smiley:

    180Mbaud = 180bps = 18MB/s

    We can write to hub at 4Bytes/clock for a block using wrlong and setq (plus setup), so 4B @ say 180MHz = 720MB/s
  • Mark_TMark_T Posts: 1,981
    Rayman wrote: »
    It'd be interesting to see if using Smartpin + Interrupt would let you juggle several I/O things in one cog.

    Things like SPI and I2C and serial are so slow compared to P2 clock speed, seems very doable...

    Well there are some pretty high SPI clock rates out there, 40MHz and up...
  • msrobotsmsrobots Posts: 3,709
    Cluso99 wrote: »
    Nice :smiley:

    180Mbaud = 180bps = 18MB/s

    We can write to hub at 4Bytes/clock for a block using wrlong and setq (plus setup), so 4B @ say 180MHz = 720MB/s

    Yes, I tried and failed. I have the data in longs in the LUT but failed over days to get my buffers running with long transfers to/from HUB.

    Finally I gave up, just transfer Bytes from HUB to LUT and vice versa, shortend everything up and made space to include decimal, hex output and string input into the COG.

    I need to check the new printf stuff in spin2gui/fastspin to maybe include that also to be compatible with them existing drivers.

    Weekend is coming...

    Enjoy!

    Mike
  • FredBlaisFredBlais Posts: 380
    edited 2019-03-03 16:50
    ***UPDATED 2***
    final code in TAQOZ thread

    ***UPDATED***

    Here is some TAQOZ smartpin SPI code (only output for now)
    input working, tested with MISO looped back with MOSI with a jumper
    and MISO looped back internally with MOSI via 'a' input selector relative pin -1 (see commented out code)
    ( 300MHZ 3.3ns PER CLOCK 10000 = 33.3us )
8 := CLK
9 := MOSI
10 := MISO
11 := SS
15000 := FREQ
CLKHZ FREQ / := N_PULSES

: CPOL0_CPHA0
CLK PIN %0000_0_0_0_000_000 8 << %1_00100_0 OR WRPIN
N_PULSES 2/ 16 << N_PULSES OR WXPIN L
MOSI PIN %0000_0111_000_0000_000_000_000 8 << %01_11100_0 OR WRPIN %101000 WXPIN
MISO PIN %0111_1110_000_0000_000_111_111 8 << %01_11101_0 OR WRPIN %100111 WXPIN
\ MISO PIN %0000_1110_000_0000_000_111_111 8 << %01_11101_0 OR WRPIN %100111 WXPIN
;

: CPOL1_CPHA1
CLK PIN %0000_0_0_1_000_000 8 << %1_00100_0 OR WRPIN
N_PULSES 2/ 16 << N_PULSES OR WXPIN L
MOSI PIN %0000_1111_000_0000_000_000_000 8 << %01_11100_0 OR WRPIN %101000 WXPIN
MISO PIN %0111_0110_000_0000_000_111_111 8 << %01_11101_0 OR WRPIN %100111 WXPIN
\ MISO PIN %0000_0110_000_0000_000_111_111 8 << %01_11101_0 OR WRPIN %100111 WXPIN
;

: SEND ( TX_BYTE -- RX_BYTE )
SS PIN L 
MOSI PIN F REV 23 >> WYPIN L
MISO PIN L
CLK PIN 8 WYPIN WAITPIN
MOSI PIN F
SS PIN H
MISO PIN RDPIN F REV
;

    Sample 
    CPOL1_CPHA1
TAQOZ# $00 SEND .BYTE --- 00 ok
TAQOZ# $FF SEND .BYTE --- FF ok
TAQOZ# $AA SEND .BYTE --- AA ok
TAQOZ# $11 SEND .BYTE --- 11 ok
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    CPOL0_CPHA0
TAQOZ# $00 SEND .BYTE --- 00 ok
TAQOZ# $FF SEND .BYTE --- FF ok
TAQOZ# $AA SEND .BYTE --- AA ok
TAQOZ# $11 SEND .BYTE --- 11 ok
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