System

System executes special instructions based on extra bits:
0x0000=> Halt the core
0x__10=> Sleep will suspend the core for a certain number of ticks
 0x0010 => SleepNop - any sleep duration of zero acts like a no-op.
 the lower 3 bits of the destination field control the sleep duration:
 0x0n10 => source field used as a number of ticks (n = 0 to 15)
 0x1s10 => lowest byte of source register as number of ticks
 0x2s10 => high byte of the lowest word of source register as number of ticks
 0x3s10 => lowest word of source register as number of ticks

Halt

The halt instruction maps to the halt opcode directly.

The following halt mnemonics are available:

hlt
halt

Sleep

The sleep instruction takes a mode specifier, and a single operand for the number of ticks to sleep.

The syntax is as follows:

Mnemonic

Sleep has the following mnemonic forms:

slp
sleep

Mode

Sleep optionally takes a mode specifier, in the form of either: .h takes the high byte of the source register as the tick count source. .l takes the low byte of the source register as the tick count source. .w takes the low word (.x) of the source register as the tick count source.

Duration

If no mode is specified, the tick count is taken as a literal in the range of 0 to 15 inclusive.

If a mode is specified, then sleep takes a register as a source for the tick count.

Examples

slp $f
sleep.w r0
slp.h c4

Nop

The sleep opcode has a special case where sleeping for zero ticks is equivalent to a nop, which is provided as an instruction for convenience.

Nop has one mnemonic, and takes no operands:

nop