Wiring Units
The components on this page generally could be constructed in
other ways, but specifying them this way just makes things cleaner and
easier.
Module: shiftLeft
This simply takes an input, shifts it to the
left a number of bits, and returns an output of the same length. This is
notably useful for branch and jump address computations.
Parameters:
|
| |
| Name |
Default |
Description |
| AMOUNT |
2 |
number of bits to shift |
| WIDTH |
32 |
bit width of inputs and outputs |
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Port Description:
|
| |
| Name |
Dir |
Width |
Description |
in |
In |
WIDTH |
input bits |
out |
Out |
WIDTH |
shifted output bits |
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| |
Symbols:
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| |
|
This component is only useful for block
diagrams.
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Module: signEx
This is a sign extension unit that simply
makes copies of the highest bit.
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|
| |
Port Description:
|
| |
| Name |
Dir |
Width |
Description |
in |
In |
16 |
16-bit immediate |
out |
OUT |
32 |
sign-extended immediate |
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| |
Symbol:
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|
This is included for completeness. You'll
want to use extender.
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Module: extender
This more complex extender unit supports
extensions of arbitrary sizes. It also has control inputs to select between
types of extensions. The possible types include zero-extend, sign-extend, align
left, and align right
Parameters:
|
| |
| Name |
Default |
Description |
| I_WIDTH |
8 |
input bit width |
| O_WIDTH |
32 |
output bit width |
| ZERO_EX |
2'b00 |
code to perform zero extension |
| SIGN_EX |
2'b01 |
code to perform sign extension |
| ALIGN_L |
2'b10 |
code to perform left alignment |
| ALIGN_R |
2'b11 |
code to perform right alignment |
|
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| |
Port Description:
|
| |
| Name |
Dir |
Width |
Description |
IN |
In |
I_WIDTH |
input bits |
CTL |
In |
2 |
controls the type of
transformation |
OUT |
Out |
O_WIDTH |
shifted output bits |
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