ST10 FAMILY PROGRAMMING MANUAL
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EXTS
Begin EXTended Segment Sequence
Syntax
EXTS op1,
op2
Operation
(count)
<-- (op2) [1
≤
op2
≤
4]
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
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
Addressing Modes
E
Z
V
C
N
-
-
-
-
-
E
Not affected
Z
Not affected
V
Not affected
C
Not affected
N
Not affected
Mnemonic
Format
Bytes
EXTS
Rwm, #data
2
DC 00##:m
2
EXTS
#seg, #data
2
D7 00##:0 ss 00
4
Содержание ST10 Series
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