GMS30C2116 Datasheet, PDF (265/322 Pages) Hynix Semiconductor – USERS MANUAL

Appendix A. Instruction Set Details
Load (I/O absolute address mode)
A-91
LDxx.IOA
Format:
RRdis format
15
OP-code 1001 00
eS
DD
87
43
0
ds
Rd-code
Rs-code
dis1
dis2
s = 0: Rs-code encodes G0..G15 for Rs, s = 1: Rs-code encodes L0..L15 for Rs
d = 0: Rd-code encodes G0..G15 for Rd, d = 1: Rd-code encodes L0..L15 for Rd
S : Sign bit of dis, e = 0: dis = 20S // dis1(range -4,096..4,095)
e = 1: dis = 4S // dis1 // dis2 (range -268,435,456...268,435,455)
DD: D-code, D13..D12 encode data types at memory instructions
Notation:
LDxx.IOA 0, Rs, dis
Description:
The Load instruction of I/O absolute address mode transfers data from the addressed
memory location, dis is used as an address, into a register Rs or a register pair Rs//Rsf.
The displacement dis is used as an address into I/O address space.
Rd must denote the SR to differentiate this mode from the I/O displacement address mode;
the content of the SR is not used.
Data type xx is with
W: Word
D: Double-word
Operation:
Rs := dis^;
[Rsf := (dis+4)^;
Exceptions:
None.