Propeller Manual

COGNEW – Spin Language Reference
COGNEW
Command: Start the next available cog to run Spin code or Propeller Assembly code.
((PUB ┆ PRI))
COGNEW (SpinMethod 〈(ParameterList)〉, StackPointer )
((PUB ┆ PRI))
COGNEW (AsmAddress, Parameter )
Returns: The ID of the newly started cog (0-7) if successful, or -1 otherwise.
•
SpinMethod is the PUB or PRI Spin method that the new cog should run. Optionally, it
can be followed by a parameter list enclosed in parentheses.
•
ParameterList is an optional, comma-delimited list of one or more parameters for
SpinMethod. It must be included only if SpinMethod requires parameters.
•
StackPointer is a pointer to memory, such as a long array, reserved for stack space for
the new cog. The new cog uses this space to store temporary data during further calls
and expression evaluations. If insufficient space is allocated, either the application
will fail to run or it will run with strange results.
•
AsmAddress is the address of a Propeller Assembly routine, usually from a DAT block.
•
Parameter is used to optionally pass a value to the new cog. This value ends up in the
new cog’s read-only Cog Boot Parameter (
PAR) register. Parameter can be used to
pass a either a single 14-bit value or the address of a block of memory to be used by
the assembly routine. Parameter is required by
COGNEW, but if not needed for your
routine, simply set it to an innocuous value like zero (0).
Explanation
COGNEW starts a new cog and runs either a Spin method or a Propeller Assembly routine within
it. If successful,
COGNEW returns the ID of the newly started cog. If there were no more cogs
available,
COGNEW returns -1. COGNEW works exactly like COGINIT (page 76) with two
exceptions: 1) it launches code into the next available cog, and 2) it returns the ID of the cog
that it started, if any.
Page 78 · Propeller Manual v1.1