GMS30C2116 Datasheet, PDF (203/322 Pages) Hynix Semiconductor – USERS MANUAL

Appendix A. Instruction Set Details
Check
A-29
CHK
Format:
RR format
15
OP-code
0000 00
10 9
d
87
s
Rd-code
43
0
Rs-code
s = 0: Rs-code encoded G0..G15 for Rs
s = 1: Rs-code encoded L0..L15 for Rs
d = 0: Rd-code encoded G0..G15 for Rd
d = 1: Rd-code encoded L0..L15 for Rd
Notation:
CHK Rd, Rs
Description:
A destination operand is checked and a trap to a Range Error occurs if the destination
operand is higher than the source operand.
All registers and all condition flags remain unchanged. All operands are interpreted as
unsigned integers.
When Rs denotes the PC, CHK trap if Rd > PC. Thus, CHK PC, PC always traps. Since
CHK PC, PC is encoded as 16 zeros, an erroneous jump into a string of zeros causes a trap
to Range Error, thus trapping some address errors.
Operation:
If Rs does not denote SR and Rd > Rs then
trap -> Range Error
Exceptions:
Range Error.