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30Mar98@15:00h
Semiconductor Group
69
Version 1.2, 12.97
C166 Family Instruction Set
Instruction Description
EXTP
Begin EXTended Page Sequence
EXTP
Syntax
EXTP
op1, op2
Operation
(count)
←
(op2) [1
≤
op2
≤
4]
Disable interrupts and Class A traps
Data_Page = (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 exe-
cution, both standard and PEC interrupts and class A hardware traps are
locked. The EXTP instruction becomes immediately active such that no
additional NOPs are required.
For any long (’mem’) or indirect ([...]) address in the EXTP instruction
sequence, the 10-bit page number (address bits A23-A14) is not deter-
mined by the contents of a DPP register but by the value of op1 itself. The
14-bit page offset (address bits A13-A0) is derived from the long or indi-
rect address as usual.
The value of op2 defines the length of the effected instruction sequence.
Note
The EXTP instruction must be used carefully (see introductory note).
The EXTP instruction is not available in the SAB 8XC166(W) devices.
E Not affected.
Z Not affected.
V Not affected.
C Not affected.
N Not affected.
Addressing Modes
Mnemonic
Format
Bytes
EXTP
Rwm, #irang2
DC :01##-m
2
EXTP
#pag, #irang2
D7 :01##-0 pp 0:00pp
4
Condition Flags
E
Z
V
C
N
-
-
-
-
-