This module deals with low-level access to CPU (and related modules) functionality, such as reading and writing memory, or enabling and disabling interrupts. It also offers access to platform specific CPU-related constants.

Functions

cpu.w32

Writes a 32-bit word to memory.

cpu.w32( address, data )

address - the memory address.
data - the 32-bit data to write.

Returns: nothing.

cpu.r32

Read a 32-bit word from memory.

data = cpu.r32( address )

address - the memory address.

Returns:

data - the 32-bit word read from memory.

cpu.w16

Writes a 16-bit word to memory.

cpu.w16( address, data )

address - the memory address.
data - the 16-bit data to write.

Returns: nothing.

cpu.r16

Reads a 16-bit word from memory.

data = cpu.r16( address )

address - the memory address.

Returns:

data - the 16-bit word read from memory.

cpu.w8

Writes a byte to memory.

cpu.w8( address, data )

address - the memory address.
data - the byte to write.

Returns: nothing.

cpu.r8

Reads a byte from memory.

data = cpu.r8( address )

address - the memory address

Returns:

data - the byte read from memory.

cpu.cli

Disables the global CPU interrupt flag if called without arguments, or a specific interrupt for a list of resource IDs if called with arguments.

cpu.cli( [id], [resnum1], [resnum2], ... [resnumn])

id - the interrupt ID. If specified, at least one resource ID must also be specified.
resnum1 - the first resource ID, required if id is specified.
resnum2 (optional) - the second resource ID.
resnumn (optional) - the #n#-th resource ID.

Returns: nothing.

cpu.sei

Enables the global CPU interrupt flag if called without arguments, or a specific interrupt for a list of resource IDs if called with arguments.

cpu.sei( [id], [resnum1], [resnum2], ... [resnumn])

id - the interrupt ID. If specified, at least one resource ID must also be specified.
resnum1 - the first resource ID, required if id is specified.
resnum2 (optional) - the second resource ID.
resnumn (optional) - the #n#-th resource ID.

Returns: nothing.

cpu.clock

Get the CPU core frequency.

clock = cpu.clock()

Arguments: none.

Returns:

clock - the CPU clock (in Hertz).

cpu.set_int_handler

Sets the Lua interrupt handler for interrupt *id* to function *handler*. *handler* can be #nil# to disable the interrupt handler. Only available if interrupt support is enabled, check here for details.

prev_handler = cpu.set_int_handler( id, handler )

id - the interrupt ID.
handler - the Lua interrupt handler function, or *nil* to disable the Lua interrupt handler feature.

Returns:

prev_handler - the previous interrupt handler for interrupt *id*, or *nil* if an interrupt handler was not set for interrupt *id*.

cpu.get_int_handler

Returns the Lua interrupt handler for interrupt *id*

handler = cpu.get_int_handler( id )

id - the interrup ID.

Returns: handler - the interrupt handler for interrupt *id*, or *nil* if an interrupt handler is not set for interrupt *id*.

cpu.get_int_flag

Get the interrupt pending flag of an interrupt ID/resource ID combination, and optionally clear the pending flag. Only available if interrupt support is enabled, check here for details.

cpu.get_int_flag( id, resnum, [clear] )

id - the interrupt ID.
resnum - the resource ID.
clear (optional) - true to clear the interrupt pending flag or false to leave the interrupt pending flag untouched. Defaults to true if not specified.

Returns: nothing.