Intel 80386
From Misc Data Digs
(Redirected from Intel 386)
Revision Differences[edit | edit source]
Steppings A0 and B0 contain two instructions not in any future instruction sets, XBTS (eXtract BiT String; opcode FH A6) and IBTS (Insert BiT String; opcode FH A7).
Undocumented Instructions[edit | edit source]
LOADALLD[edit | edit source]
Opcode 0F 07 loads all registers from memory address ES:EDI. It is only available with the 80386.
ICEBP[edit | edit source]
Opcode F1 allows for one to use the in-circuit emulator, allowing for a single-byte, single-step execution method. This wouldn't be documented until the Pentium Pro, where it was called INT1.
UMOV[edit | edit source]
Opcodes 0F 10, 0F 11, 0F 12, and 0F 13 is intended for ICE host software to cycle through memory during HALT mode.