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Logic Design, Part 8
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Previous: 'Logic Design, Part 7'
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0:08Set the stage for the day covering dividers
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0:08Set the stage for the day covering dividers
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0:08Set the stage for the day covering dividers
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1:48A quick note on the streaming schedule from Denmark
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1:48A quick note on the streaming schedule from Denmark
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1:48A quick note on the streaming schedule from Denmark
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2:56Note our use of CPython, and consider switching to PyPy for improved performance
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2:56Note our use of CPython, and consider switching to PyPy for improved performance
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2:56Note our use of CPython, and consider switching to PyPy for improved performance
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4:13Review our multipliers
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4:13Review our multipliers
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4:13Review our multipliers
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8:36Set up to cover dividers
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8:36Set up to cover dividers
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8:36Set up to cover dividers
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10:26Integer division
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10:26Integer division
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10:26Integer division
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13:45Euclidean algorithm (division by repeated subtraction)
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13:45Euclidean algorithm (division by repeated subtraction)
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13:45Euclidean algorithm (division by repeated subtraction)
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17:17Long division (finish one digit of the quotient per iteration)
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17:17Long division (finish one digit of the quotient per iteration)
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17:17Long division (finish one digit of the quotient per iteration)
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24:50Introduce euclidean_divide() as a software routine
24:50Introduce euclidean_divide() as a software routine
24:50Introduce euclidean_divide() as a software routine
25:59Introduce binary_divide() as a software routine
25:59Introduce binary_divide() as a software routine
25:59Introduce binary_divide() as a software routine
27:47Test euclidean_divide() to see that it works
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27:47Test euclidean_divide() to see that it works
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27:47Test euclidean_divide() to see that it works
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29:14Test binary_divide() to see that it doesn't work
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29:14Test binary_divide() to see that it doesn't work
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29:14Test binary_divide() to see that it doesn't work
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30:42Fix binary_divide() to left-shift the denominator by sum_bits - 1 before looping through the bits, right-shift the denominator at the end of each iteration of its loop, and preserve the original denominator for the assertion
30:42Fix binary_divide() to left-shift the denominator by sum_bits - 1 before looping through the bits, right-shift the denominator at the end of each iteration of its loop, and preserve the original denominator for the assertion
30:42Fix binary_divide() to left-shift the denominator by sum_bits - 1 before looping through the bits, right-shift the denominator at the end of each iteration of its loop, and preserve the original denominator for the assertion
34:21Run it to find that binary_divide() works
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34:21Run it to find that binary_divide() works
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34:21Run it to find that binary_divide() works
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34:41Optimise binary_divide() as binary_divide2()
34:41Optimise binary_divide() as binary_divide2()
34:41Optimise binary_divide() as binary_divide2()
39:35Run it to see that the optimised binary_divide2() works, noting the possibility to put q and r in a single shift register
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39:35Run it to see that the optimised binary_divide2() works, noting the possibility to put q and r in a single shift register
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39:35Run it to see that the optimised binary_divide2() works, noting the possibility to put q and r in a single shift register
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40:27Shift register
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40:27Shift register
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40:27Shift register
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42:11Rename the divide functions to sw_*() and introduce our hardware binary_divider()
42:11Rename the divide functions to sw_*() and introduce our hardware binary_divider()
42:11Rename the divide functions to sw_*() and introduce our hardware binary_divider()
49:00Define Example36 as a divider
49:00Define Example36 as a divider
49:00Define Example36 as a divider
50:29Simulate our divider to see that it did not work
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50:29Simulate our divider to see that it did not work
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50:29Simulate our divider to see that it did not work
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50:42Fix our divider simulator to pull the quotient out of the result, and trace binary_divider()
50:42Fix our divider simulator to pull the quotient out of the result, and trace binary_divider()
50:42Fix our divider simulator to pull the quotient out of the result, and trace binary_divider()
52:22Check out our trace of binary_divider()
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52:22Check out our trace of binary_divider()
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52:22Check out our trace of binary_divider()
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53:03Fix binary_divider() to left-shift r
53:03Fix binary_divider() to left-shift r
53:03Fix binary_divider() to left-shift r
53:55Continue to scrutinise our binary_divider() trace to see that r wrapped around
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53:55Continue to scrutinise our binary_divider() trace to see that r wrapped around
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53:55Continue to scrutinise our binary_divider() trace to see that r wrapped around
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56:54Scrutinise our binary_divider() trace now including d2
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56:54Scrutinise our binary_divider() trace now including d2
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56:54Scrutinise our binary_divider() trace now including d2
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59:01Fix binary_divider() to left-shift d2 by len(d) - 1
59:01Fix binary_divider() to left-shift d2 by len(d) - 1
59:01Fix binary_divider() to left-shift d2 by len(d) - 1
1:00:19Trace q and r at both the start and end of the loop in binary_divider()
1:00:19Trace q and r at both the start and end of the loop in binary_divider()
1:00:19Trace q and r at both the start and end of the loop in binary_divider()
1:00:35Check our binary_divider() trace to see "post r" of 240
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1:00:35Check our binary_divider() trace to see "post r" of 240
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1:00:35Check our binary_divider() trace to see "post r" of 240
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1:02:03Print the generated code of Example36's binary_divider()
1:02:03Print the generated code of Example36's binary_divider()
1:02:03Print the generated code of Example36's binary_divider()
1:02:39Check the code of Example36
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1:02:39Check the code of Example36
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1:02:39Check the code of Example36
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1:04:59Distinguish unary and binary minus in the compiler
1:04:59Distinguish unary and binary minus in the compiler
1:04:59Distinguish unary and binary minus in the compiler
1:07:25Check the newly generated code of Example36's binary_divider()
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1:07:25Check the newly generated code of Example36's binary_divider()
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1:07:25Check the newly generated code of Example36's binary_divider()
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1:10:06Remove the test unary minus from binary_divider() and simulate it to see that it works
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1:10:06Remove the test unary minus from binary_divider() and simulate it to see that it works
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1:10:06Remove the test unary minus from binary_divider() and simulate it to see that it works
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1:10:39Slightly rewrite binary_divider()
1:10:39Slightly rewrite binary_divider()
1:10:39Slightly rewrite binary_divider()
1:12:08Reflect of our restoring division, with thoughts on possible optimisations
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1:12:08Reflect of our restoring division, with thoughts on possible optimisations
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1:12:08Reflect of our restoring division, with thoughts on possible optimisations
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1:14:04Optimise binary_divider() as binary_divider2()
1:14:04Optimise binary_divider() as binary_divider2()
1:14:04Optimise binary_divider() as binary_divider2()
1:18:01Simulate binary_divider2() to see that it works
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1:18:01Simulate binary_divider2() to see that it works
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1:18:01Simulate binary_divider2() to see that it works
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1:18:23Understanding the need to 0-extend the difference of a subtraction in order to derive its sign
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1:18:23Understanding the need to 0-extend the difference of a subtraction in order to derive its sign
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1:18:23Understanding the need to 0-extend the difference of a subtraction in order to derive its sign
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1:19:14Restoring division1
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1:19:14Restoring division1
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1:19:14Restoring division1
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1:20:45Introduce nonrestoring_binary_divider()2
1:20:45Introduce nonrestoring_binary_divider()2
1:20:45Introduce nonrestoring_binary_divider()2
1:27:09Simulate nonrestoring_binary_divider() and fail the test
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1:27:09Simulate nonrestoring_binary_divider() and fail the test
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1:27:09Simulate nonrestoring_binary_divider() and fail the test
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1:28:55Fix nonrestoring_binary_divider() to mux between the correct q, before tracing it
1:28:55Fix nonrestoring_binary_divider() to mux between the correct q, before tracing it
1:28:55Fix nonrestoring_binary_divider() to mux between the correct q, before tracing it
1:30:58Check out the trace of nonrestoring_binary_divider()
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1:30:58Check out the trace of nonrestoring_binary_divider()
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1:30:58Check out the trace of nonrestoring_binary_divider()
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1:32:43Work through non-restoring division from first principles3
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1:32:43Work through non-restoring division from first principles3
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1:32:43Work through non-restoring division from first principles3
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1:35:28Enable nonrestoring_binary_divider() to fix up q and r if the remainder is negative4
1:35:28Enable nonrestoring_binary_divider() to fix up q and r if the remainder is negative4
1:35:28Enable nonrestoring_binary_divider() to fix up q and r if the remainder is negative4
1:44:47Trace nonrestoring_binary_divider()
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1:44:47Trace nonrestoring_binary_divider()
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1:44:47Trace nonrestoring_binary_divider()
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1:46:27Introduce convert_signed() for the tracing code to use
1:46:27Introduce convert_signed() for the tracing code to use
1:46:27Introduce convert_signed() for the tracing code to use
1:51:27Enable signed in the nonrestoring_binary_divider() tracing
1:51:27Enable signed in the nonrestoring_binary_divider() tracing
1:51:27Enable signed in the nonrestoring_binary_divider() tracing
1:51:53Scrutinise the trace of nonrestoring_binary_divider() to determine that the arithmetic right-shift is misbehaving
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1:51:53Scrutinise the trace of nonrestoring_binary_divider() to determine that the arithmetic right-shift is misbehaving
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1:51:53Scrutinise the trace of nonrestoring_binary_divider() to determine that the arithmetic right-shift is misbehaving
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1:53:22Enable nonrestoring_binary_divider() to perform arithmetic right-shift where necessary
1:53:22Enable nonrestoring_binary_divider() to perform arithmetic right-shift where necessary
1:53:22Enable nonrestoring_binary_divider() to perform arithmetic right-shift where necessary
1:53:38Simulate nonrestoring_binary_divider() and still fail the test
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1:53:38Simulate nonrestoring_binary_divider() and still fail the test
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1:53:38Simulate nonrestoring_binary_divider() and still fail the test
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1:54:59Fix nonrestoring_binary_divider() to shift r in the correct direction (i.e. left)
1:54:59Fix nonrestoring_binary_divider() to shift r in the correct direction (i.e. left)
1:54:59Fix nonrestoring_binary_divider() to shift r in the correct direction (i.e. left)
1:56:23Simulate nonrestoring_binary_divider(), fail the test and consult the trace5
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1:56:23Simulate nonrestoring_binary_divider(), fail the test and consult the trace5
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1:56:23Simulate nonrestoring_binary_divider(), fail the test and consult the trace5
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2:02:37Change nonrestoring_binary_divider() to pre-shift r
2:02:37Change nonrestoring_binary_divider() to pre-shift r
2:02:37Change nonrestoring_binary_divider() to pre-shift r
2:02:55Simulate nonrestoring_binary_divider() and still fail the test
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2:02:55Simulate nonrestoring_binary_divider() and still fail the test
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2:02:55Simulate nonrestoring_binary_divider() and still fail the test
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2:03:23Determine to go and think about this some more
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2:03:23Determine to go and think about this some more
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2:03:23Determine to go and think about this some more
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2:06:27Glimpse into the future on sequential circuits
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2:06:27Glimpse into the future on sequential circuits
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2:06:27Glimpse into the future on sequential circuits
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Next: 'Sequential Logic'
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