ESC              Escape                              Flags: not altered

ESC coprocessor's-opcode,source

ESC is used to pass control from the microprocessor to a coprocessor,
such as an 8087 or 80287. In response to ESC, the microprocessor
accesses a memory operand  the instruction for the coprocessor  and
places it on the bus. The coprocessor watches for ESC commands and
executes the instruction placed on the bus, using the effective
address of source.

                                                                          
Operands                  Clocks   Transfers  Bytes   Example
                        byte(word)
immediate, memory       8(12) + EA     1       2-4    ESC 6,ADR[SI]
immediate, register         2          -        2     ESC COPROC-CODE,AH
                                                                          

Notes:         In order to synchronize with the math coprocessor,
the programmer must explicitly code the WAIT
instruction preceding all ESC instructions.  The
80286 and 80386 have automatic instruction
synchronization, hence WAITs are not needed.

See also: HLT
See also: WAIT
See also: LOCK
See also: EA
Next:     HLT Halt

ESC Escape