STMicroelectronics ST10 Series Programming Manual page 80

ST10 FAMILY PROGRAMMING MANUAL
EXTS
Syntax
Operation
Description
Overrides the standard DPP addressing scheme of the long and indirect addressing modes for a specified
number of instructions. During their execution, both standard and PEC interrupts and class A hardware
traps are locked. The EXTS instruction becomes immediately active such that no additional NOPs are
required.
For any long ('mem') or indirect ([...]) address in an EXTS instruction sequence, the value of op1 deter-
mines the 8-bit segment (address bits A23-A16) valid for the corresponding data access. The long or indi-
rect address itself represents the 16-bit segment offset (address bits A15-A0).
The value of op2 defines the length of the effected instruction sequence.
Note: The EXTS instruction must be used carefully (see Section 2.7 - ATOMIC and EXTended instruc-
tions on page 38).
Flags
E
-
E Not affected
Z Not affected
V Not affected
C Not affected
N Not affected
Addressing Modes
Mnemonic
EXTS Rwm, #data
EXTS #seg, #data
78/172
Begin EXTended Segment Sequence
EXTS op1, op2
(count) <-- (op2)
Disable interrupts and Class A traps
Data_Segment = (op1)
DO WHILE ((count) ≠ 0 AND Class_B_trap_condition ≠ TRUE)
Next Instruction
(count) <-- (count) - 1
END WHILE
(count) = 0
Data_Page = (DPPx)
Enable interrupts and traps
Z
-
Format
DC 00##:m
2
D7 00##:0 ss 00
2
[1 ≤ op2 ≤ 4]
V C
- -
N
-
Bytes
2
4