Page 111 MM.Info
MM.Info(BOOT COUNT) is out of alignment with it's description.
Caused by the addition of Brownout as a reason for MM.INFO(BOOT)
It affects the rest of that page.

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VK7JH
MMedit

Thanks - done and updated in the release

In Apendix F PIO example programs many comments are preceded with a back quote instead of a single quote.
Below I have attempted to correct them all. If any have been missed or any other typos are found please note them here.

EXAMPLE PROGRAM 1
A complete PIO implementation that toggles a GPIO pins can be implemented in MMBasic as shown below.
Connect a buzzer to GP0, and hear the audio tone generated by the PIO.



EXAMPLE PROGRAM 2
Below program explains many of the above presented MMbasic functions and commands. The program reads a
NES controller (SPI) connected to the Raspberry Pi Pico. The NES controller consists of a HEF4021 shift
register connected to 8 push button switches.
Program uses: wrap and wrap target, IN, side set and delay, PUSH, PIO READ. GP0 and GP1 are in SET for
pin direction, and in side set for compact code.
The wiring is as defined in the code:



Example :

packed% will then be an integer array holding 4096/8 = 512 integers
This can then be used by the DMA for a loopback counter with DMA of 1024 32-bit words, 2048 16-bit shorts
or 4096 8-bit bytes.

EXAMPLE PROGRAM 3
This program brings everything together and uses DMA to read 128 samples from the PIO RX FIFO. For the
demonstration, GP0 to GP5 are outputs of 3 PWMS, and are, at the same time, sampled by the PIO as a 6
channel logic analyzer or oscilloscope. The 128 samples are sent to the serial port as waveforms.
This Logic Analyzer program also demonstrates PIO DMA RX, MEMORY UNPACK, the use of buffers. It
uses PWM’s to generate a test signal on gp0..gp5 for demo purpose. These same pins are read by the logic
analyzer and output to the console.
To use this Logic Analyzer normally comment out first 14 lines.




EXAMPLE PROGRAM 4
This program runs on RP2350 only and demonstrates the use of the FIFO’s as individual registers.
The PIO of the RP2350 has specific instructions to support this:
 MOV RXFIFO[y],ISR
and
 MOV OSR,RXFIFO[y]

MMBasic can read/write the 4 individual FIFO registers by use of:

PIO WRITEFIFO a, b, c, d
PIO READFIFO( a, b, c)
    a/ pio (0,1 or 2(2350 only))
    b/ state machine (0...3)
    c/ nbr (FIFO register 0…3)
    d/ data% (32 bit integer value)

The program configures the FIFO for individual reads, then writes some values in these register.
It starts the PIO that updates 2 of the 4 individual FIFO registers. Then MMBasic reads the values
to show only 2 registers have changes, and no data shifted (as would happen in RP2040 FIFO).



The expected output is:
3 RXFIFO registers before running the program
0        100
1        200
2        300
3        400

3 RXFIFO registers after running the program
0        100
1        200
2        3
3        4


EXAMPLE PROGRAM 5
Finally an example program showing how multiple state machines can work together, each one triggered
from an interrupt from the other one. Note also the use of .LINE NEXT as starting point of the second
program, and the use of x=PIO(NEXT LINE) to determine the starting point of the second program.

IRQ 1 sets and IRQ. When the other state machine is waiting WAIT 1 IRQ 1, it continues after IRQ 1
found set, and clears the IRQ 1 at same time.


Edited 2026-09-24 11:03 by phil99

uuppsss  missed some changes...

program 3
‘--------------------------------SUBS MMBasic --------------------------

program 5
‘test for PIO IRQ's on PIO 0 state machines 0 and 1

/Peter63

Manual updated with the fixes in the RC1 release

Thanks Peter and Peter.

It would appear I had some of the line lengths wrong for the PDF formatting.
Some adjustments needed.

EXAMPLE PROGRAM 3


EXAMPLE PROGRAM 4

Edited 2026-09-24 19:04 by phil99

Perhaps an addition to the end of Special Device Support - IR Remote Control

"Subroutines for other IR Remote Control Rx and Tx protocols can be found on Fruit of the Shed.
https://fruitoftheshed.com/wiki/doku.php?id=mmbasic:start"