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Bit deposit. Deposits a value into a specified range of bits. Syntax | |
bitd (value position length target)
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Formal Declaration | |
bitd:any (value:any position:s16 length:u16 target:any)
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Parameters | |
- value
The value to deposit into the target. Its type is restricted to the INT and PTR classes.
- position
This parameter specifies the starting bit position (positive
value) or the ending bit position (negative value) of the deposit. Regardless
of the size of the target, bit positions are always numbered from left to
right. The leftmost bit of the target is bit 0.
- length
The number of bits to deposit. This value may not exceed 64.
- target
The expression in which to deposit the specified bit pattern. Its type is restricted to the INT and PTR classes.
This function is sensitive to the type of the target parameter.
As examples, if a S32 or U32 value is passed, the format of the word
(start/end positions) is as follows:
1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+---------------------------------------------------------------+
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+---------------------------------------------------------------+
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If a S16 or U16 value is passed, the format of the word (start/end positions)
is as follows:
1 1 1 1 1 1
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+-------------------------------+
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+-------------------------------+
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Examples | |
For our example, we use a 32-bit word containing the bit pattern
for the hex value 4015381f:
1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+---------------------------------------------------------------+
|0 1 0 0 0 0 0 0 0 0 0 1 0 1 0 1 0 0 1 1 1 0 0 0 0 0 0 1 1 1 1 1|
+---------------------------------------------------------------+
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$nmdebug > var xx:u32 4015381f
$nmdebug > wl bitd(0,#30,2,xx)
$4015381c
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Deposit the value 0 into the last two bits of XX.
$nmdebug > wl bitd(3,-#1,2,xx)
$c015381f
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Deposit the value 3 (11) into XX, ENDING at bit position 1.
$nmdebug > wl bitd(2d,-#9,6,xx)
$4b55381f
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Deposit the value 2d (101101) into XX, ending at bit position 9 with a length
of 6 (start position would be 4). Limitations, Restrictions | |
The value to be deposited is truncated as necessary on the left to fit
within the field width of length. If an extended address target is passed, the deposit location must fall
entirely within the 64-bit offset part. Since EADDR types have a total
of 96 bits, the valid bit positions are 32 through 95. |
