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FFFFF
0000C
Lo
wer 64 KB
0FFFF
10000
PC.19:0
PC.19:0
PC.19:0
±32 KB
PC.19:0
±32 KB
Addressing Modes
Figure 4-21. Overflow and Underflow for Symbolic Mode
Length:
Two or three words
Operation:
The sign-extended 16-bit index in the next word after the instruction is added to the
20 bits of the PC. This delivers a 20-bit address, which points to an address in the
range 0 to FFFFFh. The operand is the content of the addressed memory location.
Comment:
Valid for source and destination. The assembler calculates the PC index and
inserts it
ADD.W EDE,&TONI ;
Example:
This instruction adds the 16-bit data contained in source word EDE and destination
word TONI and places the 16-bit result into the destination word TONI. For this
example, the instruction is located at address 2F034h.
Source:
Word EDE at address 3379Ch, pointed to by PC + 4766h, which is the 16-bit result
of 3379Ch – 2F036h = 04766h. Address 2F036h is the location of the index for this
example.
Destination:
Word TONI located at address 00778h pointed to by the absolute address 00778h
106
CPUX
SLAU272C – May 2011 – Revised November 2013
Copyright © 2011–2013, Texas Instruments Incorporated