HP 10314D User Manual page 28

Table 2-2. Status Field Encoding
80386
Status Bit
10 9 8 7 6 5 4 3 2 1 0
Cycle Type
Interrupt Acknowledge xxxxxxxxOOO
l/ORead xxxxxxxx010
l/OWrite xxxxxxxxOll
Opcode Fetch xxxxxxxxlOO
Halt/Shutdown xxxxxxxxlOl
Memory Read xxxxxxxxllO
Memory Write xxxxxxxxlll
Valid Bytes
in
Transfer
(from LBEO through
LBE3)
Double Word
(all
bytes valid) xxxOOOOxxxx
Higher 3 Bytes xxxOOOlxxxx
High Word xxxOOllxxxx
Byte3 xxxOlllxxxx
Lower 3 Bytes xxxlOOOxxxx
Middle Word xxxlOOlxxxx
Byte2 xxxlOllxxxx
Low Word xxx1100xxxx
Byte 1
xxx1101xxxx
ByteO
xxx1110xxxx
Size of Transfer
16-bit Transfer xxOxxxxxxxx
32-bit Transfer xxlxxxxxxxx
Note: X
=
don't care. The actual status field is a 15 bit field; however, bits 11 through
14
are not
shown
since
they
are
"don't
cares."
Analyzing the Intel 80386DX
2-6
HP 103140
80386DX Preprocessor Interface