122-32000 Parallax Inc, 122-32000 Datasheet - Page 281

• Manufacturer Part Number: 122-32000
• Description: MANUAL PROPELLER
• Manufacturer: Parallax Inc

Specifications of 122-32000

• Accessory Type: Manual
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With/related Products: Propeller Education (PE) Kit
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

Note that each cog’s output states are made up of the OR’d states of its internal I/O hardware
(Output Register, Video Generator, etc.) and that is all AND’d with its Direction Register’s
states.
An I/O pin actually outputs low or high, as specified by the cog’s output states, if, and only if,
that pin’s bit in that same cog’s direction register (
specifies the pin to be an input and its output state is ignored.
This configuration can easily be described in the following simple rules:
If a cog is disabled, its direction register is treated as if were cleared to 0, causing it to exert
no influence on I/O pin directions and states.
Note because of the “wired-OR” nature of the I/O pins, no electrical contention between cogs
is possible, yet they can all still access I/O pins simultaneously. It is up to the application
developer to ensure that no two cogs cause logical contention on the same I/O pin during run
time.
Using OUTA
Set or clear bits in
the corresponding bits of
The
inputs. The
result is that I/O pins 25, 21, 20, 8, 7, and 4 output high and I/O pins 6 and 5 output low. I/O
pin 30 is set to an input direction (according to
and the pin remains an input according to this cog.
Using the optional Pin(s) field, and the post-clear (
cog can affect one I/O pin (one bit) at a time. The Pin(s) field treats the I/O pin registers as
an array of 32 bits. For example:
DIRA := %00000100_00110000_00000001_11110000
OUTA := %01000100_00110000_00000001_10010000
DIRA[10]~~
OUTA[10]~
OUTA[10]~~
A. A pin outputs low only if all active cogs that set it to output also set it to low.
B. A pin outputs high if any active cog sets it to an output and also sets it high.
DIRA
line above sets the I/O pins 25, 21, 20, 8, 7, 6, 5 and 4 to outputs and the rest to
OUTA
line sets I/O pins 30, 25, 21, 20, 8, 7, and 4 to high, the rest to low. The
OUTA
to affect the output state of I/O pins as desired. Make sure to also set
DIRA
to make that pin an output. For example:
4: Spin Language Reference –
'Set P10 to output
'Make P10 low
'Make P10 high
DIRA
~
) so the high in bit 30 of
DIRA
) and post-set (
) is high (1). Otherwise, that cog
Propeller Manual v1.0 · Page 281
~~
) unary operators, the
OUTA
is ignored