Overview Overview of the Instruction Format
Each entry in this list includes information on which flags in the
8088's flag register are changed, and how they're changed. Since
there are 9 flags in the flags register, the flags display is very
compact:
Flags: O D I T S Z A P C
0 * * ? * 0
? Undefined after the operation.
* Changed to reflect the results of the instruction.
0 Always cleared
1 Always set
--------------------------------------------------------------------------
The timing charts show timings for the 8088. Since the 80x8x
processors execute instructions in fewer clock cycles than the 8088,
these charts represent the worst case.
Operands This field gives the list of possible operands and
addressing modes for each instruction.
Clocks Number of clock cycles required to execute the
instruction on an 8088. Effective Address
calculations (EA) take additional time, as outlined
in the EA table.
Transfers The number of memory references. 4 clock cycles are
required for each memory reference.
Bytes Number of bytes in the instruction.
--------------------------------------------------------------------------
Note: The additional clock cycles required to reinitialize
the instruction que and fetch the next instruction
after a control transfer instruction (such as JMP or
CALL) is already included in the timing tables. Two
clock times are listed for conditional transfer
instructions (such as JZ); the shortest time is for
the case when there is no transfer.
Seealso:
This page last updated on Fri Nov 30 10:49:50 MSK 2001
Copyright © 1992-2001, Vitaly Filatov, Moscow, Russia
Webmaster